Confused

I am currently with someone that I have been with for almost 4 years now. (sept 28) I am engaged to this person and I love him very much. I guess you would ask what am I confused about. We had a lot of problems throughout our relationship, but hey who doesn't. He has 3 children, 2 biological and 1 he takes care of (doesn't he sound great). That causes a lot of chaos because there is a baby's mama and yes she is still around(when she wants to be). I found out about 1 1/2 years ago that he cheated on me, but not with her. Ever since then and even a little before I wondered if we were meant to be. I wear his ring and am completely committed to him but I am not sure if this is what is supposed to be. We fight very often about anything and everything. I could just use some advise. I have a friend that is a guy and he is so much nicer, and he talks to me (and listens!) and is very good with everything, he is in college, and working and rents his own house. I am just wondering if I deserve better or is this how they all act before they get together with someone. Because my fiance was just like this other guy is acting when we first got together too, then things changed (really fast, and not for the good). Let me know......