Is it normal to feel like this? - long distance relationship

Okay, so I am 19 and with a really good guy. He respects me, he is there when I need to talk to him about things, he supports me when I have goals (no matter how out there my goals might be) and he can make me laugh even when I am at my worst.

A couple weeks ago, we had our second fight (we've been together for a year and a half). Both of us said things we definitely shouldn't have, but we talked over the phone a few days later, calmly explained what we had been thinking and feeling, and we were done with it. Then my mom tells me that I should break up with him because I told her one of the things he said. She said I could do better, that my bf would be just like my dad (my parents are divorced), and that he and I seemed more like “really good friends trying to start something that just isn't there.”

At the time I disagreed with her on all of that, but I have noticed lately that I am focusing on what I dislike about him or what he has done wrong. I feel like I have no choice now but to break up with him, but the idea of it will often put me in tears or make me feel incredibly guilty. I worry that I am not doing the right thing by staying and I worry that I wouldn't be right to leave him either. And sometimes I feel like the spark really is gone, but then I think of what kind of person he is and how we aren't like a typical couple that can see each other a few times a week and do things to keep it alive as easily.

Is it normal to feel like this, or am I just being crazy and destroying something good?