Should I stay or should I go?

My husband and I got married because I was pregnant. I was still in school and I was terrified! When I was pregnant he made me feel terrible about myself. I was so depressed. I felt disgusting and undesireable. His temper would come out and he would always yell and me and put me down. i was miserable. Yes, i was hormonal but iti s hard to forgive and forget.I feel like I have settled. He never got down on one knee when he proposed. I barely saw him during our wedding reception. This is just NOT what I pictured when I saw myself as a married woman! Our marriage has been very bumpy, and we have a beautiful nine month old son. I have wanted to leave so badly and I threatened to and he changed. I just can't forget and forgive how he treated me when I was pregnant. I don't feel that his "change" is genuine. I feel like he just supresses his anger issues. I feel like I have changed into a bitter and cynical married woman and I am only 23! I used to be one of those people that believed in soul mates and true love and now, I am stuck in a marriage that is miserable. I am not in love with him anymore. I tried so hard when I pregnant and I simply had the lowest self image. Now that I have my self confidence back I want to leave. I mean he is not physically what I wanted in a husband. I am still in school and have about a year left until I will have my Bachelors. What should I do?? It's like that song: Should I stay or should I go?