What do I do about my commitment issues?

Okay, I'm only 17 I understand that it's not too serious, but I feel guilty and feel as if I'm a horrible person. I dated a girl in 7th grade, but ended up breaking up with her after 4 months or so. Then I met another and "dated" her until my Sophomore year in high school. Let me make it clear that all we ever did was hold hands twice, and no physical contact ever. During my Freshman year, I dated another girl, knowing that I was already with another person, and then another after breaking up with this one for a week. I didn't tell 3-year girl or girl-after-1-week-girl until summer that year. But the thing is, with 3-year girl, I've broken up with her a total of three times and the same with the girl-after-1-week-girl. I broke up with both of them my sophomore year, and then I dated a girl for a month and then left her for my current girlfriend of a year and a half. I cheated on her 3 times and told her about it because I felt guilty. We're still together and I'm glad. What I truly desire is a long term relationship, but my philosophy is that if I am to be with someone for a long time, then I guess I do have to look for appearances first. I don't go after obvious people-who-are-just-in-it-for-sex, but I feel as if I really only cheated because I'm not getting any emotional fulfillment from relationships. I feel as if the girl is never really there for me. I'm being honest, I make it clear that I will do anything reasonable to keep their happiness and know that I'm not a horrible boyfriend in that aspect. My father has 2 children with different people and is currently divorced with my mom right now. From what I've heard, he never has more than $20 in his pocket. I try my best not be like him but I find myself doing so anyway. I don't want another relationship but I keep feeling as if I have this urge to start another one. I truly love the girl I'm currently with but I keep remembering that I cheated on her 3 times. Again, I don't want another relationship but I always have the urge to start another one. What's exactly is..."wrong" with me?