The gist of it was that I got majorly friendzoned even though we had a relationship already. We are still really good friends now.
Reasons were because of the nature of our careers and that we were both too competitive, especially since we were in the same field. We were afraid that if we outdid each other, the other would feel horrible. At the same time, we didn't want to hold back just for the sake of each other. She was also worried because even though she refused to admit it, she got jealous when other women look and smile at me (she still gets a little uneasy and protective now). Coupled with me using to be quite promiscuous when I was younger kinda got her a little less trusting with me even though I'd never cheat on anyone.
I took the break up pretty hard, especially when she got into a relationship pretty soon after that...