I'm having unusal trouble with relationships.

Hello everyone. I'm currently 18 and as title says,I'm having some trouble with people. So here's my story (i believe it's gonna take a while to read, so i suggest you make a coffee of smth just so you wouldn't get bored :) )
Back when i was 12 i realised i don't have any friends. Like, i was a part of group of friends(sound weird, imo XD), but they weren't really my friends. They never invited me anywhere, didn't care about how i was doing etc, even though i tried to be nice with them and was asking them how they were doing. It wasn't easy, but i decided to leave, because it felt like having a dead pet. I've felt pretty lonely, until l met one girl.
Pretty much she was a shy hermit without any friends like me. We get along each other. A bit later i asked her to be my gf, even though she rejected me, she begged me to stay as a friend and even cried about it. Of course i was a bit dissapointed, but after all i've got what i wanted, right? I've got a friend. And she's happy as well that i'm with her.
4 years passed, we were still friends. Her personal life got better - she's got some new friends. And so in one day we decided to walk. During the walk i ruined our relationships. Want to know how? I asked if we (i,she and her new friends) can go somewhere together sometime. I totally didn't...i don't know..."forced" her to do as i say and she was in a great mood until that question.
She always told me how good/nice/great/other word that feels good to hear i am. But after that it was like she became completely different person. She told how egoistic i am, never listen to her, doesn't allow her to have some personal space...and them she left. Left for good.
I must admit, it was a lot worse than leaving my ex-pseudo-friends behind. At one point it even became something...radical.
I don't accept depression and stuff like that like diseases, but i believe i had(and having) one. I was just sitting and talking to myself(as strange as it sounds, it's just the way i call "thinking") and it was like i was filled with hatred. I just wanted to go outside and hurt people. Mentally, physically(mostly this one), it didn't matter. But apparently i stopped myself.
"Maybe i really didn't listen to her as much as she wanted", "Maybe she was afraid i would get on well with her friends and would forget about her" " Maybe those new friends are simply better" - that kind of thoughts i had. I overcome my let's call it "revenge on humanity" thing, but feelings like "What if i let myself do what i want?" didn't left me completely. And so that argument inside of me were going on for some time. Until I've met another girl(how original)
I completely felt in love with her. Like, old girl was just a good person and opposite gender, so i just tried to became a couple with her and stuff, but i totally loved new one. Again, we got along with each other and after sometime i told her that i love her. And she replied the same way. Boy, i was so happy =D.
I thought that my good side totally won that vengeful side.But,well, unfortunately, she's the reason i registered on this forum and so you know everything wasn't so perfect.
I have a plush animal, that i wanted to gift her. So i told her that i have a little surprise for her. And guess what? She was telling me how much she hates surprises and everything that's not under her control and now she...doesn't speak to me anymore at all. Like those almost-2-years relationship never exicted, just faded away.
She's reading my messages, but never answers and she isn't answering the call. It hurts even more than friend-girl story, because i though i were something essential for her, just like she was essential for me or at least that i wasn't nothing for her.
Just like friend-girl girl she told me all that stuff how good i am and we were pretty close to each other so i never suspected her to disappear like that.
Excuses of both girls feel like they both didn't like me at all from the beginning and they were just looking for a good opportunity to get rid of me and still end up like a good person. Like "It's not me leaving him behind, he hurted my feelings like a complete moron he is and that's why i don't want to speak with him" (Btw, we never argued before that at all, both sutiations i described are first times...even though it's hard to call this an arguement...sorta...)
So, why did they do that? What's the point? Is that the way good persons behave when it comes to getting rid of someone? Hell, i'd prefer to stuck with bad people rather than this, at least it's doesn't feel that bad.
Most importanly, i returned to vengeful side and this time it's a lot stronger, and i don't like it at all. I don't want to hurt anybody, yet at the same time a want...
So here are some questions i want to ask you:
1)How do i find true love? As pathetic as it sounds, i even looked for love guides on internet - yet i still have no clue what and where i've done wrong. I cared about them as much as i could and was ready to do anything for them and make them happy at all cost.
2)Again, why is this happening like this? Wouldn't it be easier to tell "you know, i don't like you" at the beginning? Did they both try to make it less painful for me?(Well they sure made it even worse)
3)What do i do with my hatred? It's really hard to hold myself, that's why i'm looking for help here. Unfortunately, i've got enough strenth to hurt other people and that worries me the most :(
4)How can i trust people at all? I can't get over it, i made the same mistake twice. Seems like no matter what i'm still remaining nothing for people. Even if they would tell, that i'm important for them, there's no guarantee our relationships wouldn't end up the same way...or even worse.
Thank you for reading all this. Even if you didn't read all, thanks for your attention anyway. I hope you wouldn't laugh at me. But to be honest, despite the fact, that i fell pretty lonely and sad, the way i lost those 2 girls is just ridiculous.
P.S. In case there're any(a lot of i'm sure) grammar mistakes, i apologise - english isn't my first language.

Its always interesting reading this stuff, I think when I was 17-18, I probably started going on dates with women, like you, things never worked out.
I had girls that I thought were into me and suddenly? Poof. Gone, they didn't give a crap about me anymore. It hurt.

However, as I've gotten older, ive realized so many things about about relationships, dating, love, interest, and women.
All the failures, started coming together. I was a very inner intuitive person, I critiqued everything, dissected things. Like, "this woman respondedicated positively to this, this and this", she blew me off after this happened, it seemed minor? Was there something leading up to that that was the real cause?

Sometimes women just aren't that into things or sometimes new people come along. You never know all about a woman's life or what she really thinks about you.
Words are cheap, actions show everything.

The best thing I can recommend is to learn great communication, voice what you want in a non-needy way, but never be pushy. Make your interest in women clear, and just go with the flow.

Okay the questions..
1) What is true love? The fact is, we are creatures that adapt and change, we may be interested in things at one momented, and no longer interested later. You simply caring for a woman and wanting to make her happy sounds sweet, and it's a good thing to do that, but it doesnt relate directly to what HER interest level is. Meaning, just because you do these things it doesn't mean she will be or become interested, as you've discovered. Always be aware of what the other person is putting in, are they reciprocating??

2) As I said, interest levels change. I've had women very interested in me, and had them do this to me as well. It's not that they weren't interested, its that I made mistakes or another guy entered the picture, or some other dynamic occurred. Interest levels change. They probably were interested in you at first, like the girl that told you she loved you, I think it was probably real.. IN THAT MOMENT.

3) Never be a bitter lover. Always be positive, even when life sucks. Take time to soak alone, and feel your emotional pain, then spring back up. Engage in good hobbies, strive to be a good person, you're 18, start working out. It will do wonders for you, physically, mentally and emotionally.

4) trust people is part of loving. You show up to give, when you're taken for granted, not valued, or notice it isn't being reciprocated, you retract. You need to show up to give, dont hold back. (Although take measured steps to release your feelings, such as "it felt great seeing you today" vs. "I can't live without you" with the girl youve been talking to for a week)

Reading your response reminding me in some ways about when I was younger, now I'm 25, I have a decent understanding of all of this stuff, but I still get burned. Amd sometimes i still make mistakes. That's the reality, sometimes you win, sometimes you lose.

Thanks for your reply. Is feels good to know i'm not the only one having that sort of trouble, even if having trouble in general is("was" in your case) something bad.
Even though your message gave me the idea on how to react to all this, can i ask you one more question? It's not like i need an advice here, just pure interest. After all, i believe you figured it out for yourself, since you have a decent understanding of all of this, as you said =). You told me that people can love someone/something for one moment, but don't care later. So then, how does marriage works? I thought people're divorcing because of something, you know, like if they can't stand each other, doesn't communicate, cheated on each other and stuff. But if love can just disappear at one moment, than what? If your wife lives with you until your very last day than what's this? True love of pure luck?

Things just don't work out at times. People grow apart, people quit putting their best foot forward, they take it others for granted, etc.
Marriage and relationships aren't all fun and laughter, they're difficult at times. You need to compromise, at times you'll get into disagreements, people make mistakes, people marry for the wrong reasons (settling) etc.

You need excellent communication skills and other good qualities to show up as your best self.

Not pure luck, its people that are healthy, and want things to work out. Marriage really is a journey together, you work together to meet each other's needs, or you grow apart.

Course there's crap marriages that will last forever as well. People that stay together solely for the sake of keeping a marriage or only for the kids.