Stop messing with my heart....?

I posted this in ask the females threads but i feel like maybe it should go here as well? let me know what you all think!

ok, so i never got the guts to post my problems to the site but i'm to the point where i dont care. This will be a long one but anyone who can help please do!!

I met this girl about a year and a half ago, and right away i knew i liked her, she was different and i thought it would be good for me. So we started hanging out every day for like 4 to 5 hours, and texting all the time. But one night when i hadnt planned on anything she initiated things. We were laying on her couch and i was just rubbing her stomach to confort her. While watching the movie she turned around to me and said do you have to do that? So, i stopped and asked what? She said breathing on my neck and rubbing my stomach, it's kind of turing me on. I was like oh, my bad... so i stopped, and she eventually turned around and said no, please keep going. So i continued. after a bit she turned around and got on top of me and i was like can we not do this, i dont want to get hurt, and idk how this bothers you. So she was like how does that bother me? so she said how about if i do it to you, so she started rubbing my abs and kissing my neck, it tuned me on but i played hard to get, so i said nothing. so she said "i guess we should just be friends" i'm like what are you talking about, i dont want to get hurt if you just want a quick hookup? so that night nothing happened, and the next week we had the same thing but we did hook up, and she said dont worry about getting hurt nothing will change between us.

We continued to hookup without "dating" for about 2 to 3 months, where i would buy dinner and take her places like a couple would. Then I made the biggest mistake of my life and introduced her to one of my lamer friends. They started talking behind my back, and eventually a month later they were dating, but the thing is we kept hooking up while they were dating up until April, where she would tell me, i dont think he has a penis, so i feel like i was makeup sex. Then it all stopped and she got really mean to me and never wanted to hang out or do anything again. Summer came and we started hanging out a lot again, but behind his back(he and i are nolonger friends) and he would check her phone to see what guys she was texting, tell her who to talk to, and things she could and couldnt do. Her parents went out of town for a week and she had a week long party at her house when her boyfriend and parents were both gone. He called the house while she was having a party and got pissed, then the next night we were at Hookah, and then going back to party more he called her and she was Just like look i'm with brad, and he said I'm never talking to you again. She was depressed for a week and i tried to be there for her as best as i could.

Things were back to normal and i dont think i had more than best friend feelings for the girl because i was kind of moving on. The next thing i know is he is back in her life at the beginning of the school year where none of her friends would see her and she wouldnt be at campus on the weekends. Over winter break we hung out a lot and he found out and things were a little shaky, then back at school, she stayed the night at my apartment and we watched the movie where she layed on me b/c she was tired like she usually would, and then i was on my computer and she layed in my bed and i was like i'm deff sleeping in there, with or without you. she said no and i just decided not to fuss with it. So i curled up on my couch to fall asleep, and the next thing i know she called my name and asked where i was and that if i didnt get in that bed in 5 seconds she was going to be mad because she wasnt letting me sleep on my own couch in my own apartment. So, i went in and laid in my bed with her, and told her look if we end up cuddling tonight lets not think anything about it and she was like, idc that doesnt bother me. So we just talked started having a heart to heart, and i was joking with her a bit like i always do and started tickeling her, and then we ended up spooning, and then tickeling again. The next thing i know is she is on top of me straddeling me. By this point i was turned on, but i had no intentions in hooking up with her, But one thing led to another and i was rubbing her crotch, and tickeling her. Werid thing is she only stopped my hands tickeling her and did nothing to my other hand.

We ended hooking up and sleeping together, it was the best sex i had had in a LONG time, and i feel like it kind of meant something... The next morning was usual and so was the day, but i was on facebook that night and saw she was just in a relationship with her ex boyfriend on that monday before! i was like uhh hah, oops? so shit hit the fan the next weekend and her boyfriend broke up with her b/c he doesnt trust her at college and what she does. So he hacks onto her facebook changes her password, delets a lot of her friends and bitches her out and calls her names, like he did the last times they broke up. By now, i had found i had strong feelings for her, but she and i had been best friends for about a year and three months now. I've talked to her roommate and she doenst know what i should do. She is taking her breakup with her ex pretty hard because she feels like she will be lonely and all that stuff. Should i Tell her that i have strong feelings for her? But if i dont, i feel like she will go back to her stalking/controlling boyfriend and i cant take that again because i care about her so much What are your thoughts on this whole years crap?

Thanks!

And also, I cant get her off my mind and the thought of not having a chance with her makes my heart ache...