Objective look at my relationship

Hello everyone,

I need a way to express myself to someone who can be objective about my relationship. I am 20 years old. I have been in a relationship for 3 and half years and a year of that I have been living with my girlfriend. I never had a serious relationship before this one and I am very confused. When we started texting and getting to know each other it was the first time I could talk smoothly to a girl, without forcing any topics, just fluent conversation.

Then we started dating and were together for about 6 months when we said I love you to each other. I was afraid to say that because I wasn't sure she felt the same way, but everything went well. After that a topic of ex relationships/crushes has come up and I told her that I had a crush on a girl who was going, at that time, to the same class as me and asked her out but she declined. She was a little worried because she had bad experience with her ex boyfriends. After about 7 - 8 months we started having sex, it was really great and I felt really happy. I still watched porn from time to time thinking it was just something to take the edge off. A couple of times I fantasized about a girl next door and about the girl I asked out. I confessed that and she was really hurt.

Since then she has lost her trust in me and I haven't done much to fix it. I lied to her sometimes about some irrelevant stuff and that just made it worse. It was my birthday and I haven't really introduced my girlfriend to my friends before that so I invited her to my party, it was just a couple of my closest friends and her. We were childish then and I acted differently around her and around my friends ( dirty jokes, boasting, alfa male competitions and such ). She saw that difference as another lie. When she came to the place I was celebrating my birthday one of my friends was acting like an idiot towards her and I didn't protect her. He also asked me why did she have to come and instead of protecting her again I said something like I had to invite her. I realise now how idiotic that was. I told her about what my friend had asked me and what I responded.

She asked me if I was watching porn and I said no even though I was. I confessed after a month and she cried a lot. I felt really bad for hurting her like that. I tried stopping watching porn since then. She didnt ask me to stop, but I knew it was wrong to watch it. I knew she felt like she wasn't sexy enough for me. However, I still watched it rarely and felt guilty after that. She also asked me if I was attracted to other women again I said no but I lied again. To me, explanation of cheating is a physical interaction with another person (kissing and sex), but she feels cheating is not only physical but it can also be mental with thoughts and fantasies. I was attracted to other women but I would never act on it. We started living together as we went to college. From time to time I would think about how would it be if I wasn't in a relationship (living a college life) and I would always come to the conclusion of its just a "grass is always greener" type of thing. One night I made a profile on a dating site and looked some profiles and then logged out. I never thought I would cheat on my girlfriend and I still believe that, I haven't been on that site since.

I haven't confessed this to her because I'm pretty sure we would break up, and that's a thing I don't want. I feel Love towards her, but when I read all this things I have done while she has really been the only one working hard for this relationship I doubt in my own feelings. She has always stood up for me, she always made me feel better when I was sad, she always put me in the first place and I know she loves me. I didn't do the same, I did put myself first in a lot of decisions. Her grandfather died the same day I was going to visit my family and instead of going with her to the funeral I just went home. I wasn't there for her. I was selfish sometimes and I tried not being selfish but every once in awhile I would do something completely selfish.

We have great sex, we really do and I find her the most sexiest person on the planet. I do get horny watching porn but the amount of her sexyness is overwhelming. But as we lived together I used to play a lot of computer games and she encouraged me to do so saying she really likes to watch me play, she did also play but less than me. We falled into a routine in which I would play games for 8 hours and she would fall asleep and I would then go to bed and we wouldnt have sex more than once a week. Even when we do have sex 3-4 consecutive days I still lust for other women.

She is the only person I can confide to. I lost the friends I had, I never felt connected to my family because my parents are divorced. I feel such immense Love towards her, but my actions say completely otherwise. As I write this and remember all the selfish and disgusting acts I have done I feel like I don't deserve her Love. I wonder am I unable to love or I'm just an a$$hole. I saw a girl today who I thought was hot and had a mini scenario in my head of how would I talk to her. That terrified me. I honestly don't know what to do. I don't want to break up because I love her and she loves me, but I can't ignore the things I have done either.

Thank you for reading all of this and I would appreciate any comments and help.