Is it time to end a 3 year relationship with my girlfriend ? Looking for some input - Complicated?

Hey;
I’m a 23 yr. old male who has been in a relationship with a 22yr old girl for 3 years now. We are both students and met in college.
For quite some time I have been doubting if I should stay with her or if she is the right one for me. I seem to be doubting a lot in general and she happens to be one of those things so I treat her very unfairly many times by saying hurtful things to her like ‘I’m not sure If i love you’ or I think you are not the right one for me. This is due to my OCD and it gives me a hard time because I do not know if it is my obsessions that are feeding this doubt and making me want to doubt her or if it is real emotions. Either way; i am sort of disconnected from her on many levels but at the same time I do love her and I don’t want to leave her.
The things that make me doubt are the fact that we have very little in common; she doesn’t like to go out and hang out with people or party once In a while. There is a good chance that if I like something she dislikes it and, yes, its a manner of personality and taste.

Whats more important are the feelings that I get from this relationship. I am constantly comparing her to other girls and thinking to myself; ‘why is she not like all the other girls?’ I seem to dislike certain personality traits she has such as being not very social, not talking about her feelings ever. Its always like ‘I feel bad’ and then I ask her way and she says she does not want to talk about it. Also that I think I hurt her way too many times and because of that she doesn’t trust me anymore. She thinks I dont love her and that I will break up with her all the time and so she cannot commit really. I feel like I made many mistakes and hurt her way too often and somehow I am scared that this relationship is doomed and will never work simply because I cannot repair the damage done.
I’d like to hear about how I can make the flame spark up again and How to properly love her again. How to look forward to seeing her and how to make a phonecall feel good instead of not knowing what to talk about and feel pressured all the time. I want to know how to look forward to seeing her again and not have this dreadful feeling of pressure each time I see her because I don’t know what to say/do act to make her happy. How do I get out of this hole? is the only way out a breakup ? I just want everything to be okay again and me to love her again the way I used to. Obviously I learned that one cannot force love, it has to come by itself. But how?