My mom may have been the worst person in my life

Yeah, she raised me, and she never let me starve. But, I hate her so much for all the things I went through when growing up. I'm 21 years old, and I'm a junior in college. I am proud to say I am working hard for a better future, no thanks to her. I'll give a brief story of my childhood and the relationship between my mother and me. My mom was a single mother of two, my older brother and I. She re-married and had a third child. I was 5 years old when she re-married and when my father died. Throughout my childhood, my stepfather would beat my older brother and me. In fact, one time he even hit my older brother so hard that he bled from his back. One time, my stepfather made us lick salt off each other's backs. This was the way we were disciplined.She allowed all of this. My parents cheated on each other, and at age 6, I knew exactly what was going on. After all the abuse and beatings I took from my step dad, my mom divorced him because she started seeing someone else. This happened when I was 12. I remember being depressed and angry with life. Oh, I remember hating her so much. At age 14, I can say my mom had lost complete control of what I was doing. I started going out with kids from high school. Meanwhile, all she focused on was working because she was single again. She blamed us for misery. She blamed us for no guy wanting to be with her. I hated my life so much. I was extremely depressed. So, I started hanging around the wrong people. Long story short, I was raped at age 15. From that rape, I got pregnant. I gave birth, and she now has custody over my son. Whenever we argue, she blames me for the decisions I made when I was a teen. I honestly don't expect any better from her. She's an uneducated foreign immigrant who doesn't know any better. It's a struggle to build a healthy relationship with my son, let alone fix the mess between her and I. Now, I'm working towards a bachelor of science in nursing, and I just think it's better to focus on myself only. Sometimes, I even felt like leaving everything in the past. I never wanted to become pregnant at 15, but my mother set the stage for it. I can only blame her. I was going to give my son for adoption after giving birth, but she said she wanted to take responsibility to raise her grandson. I thought it would be a good idea, but I don't think she will raise him like he deserves. Deep inside, I just want to go away and start my life all over. I understand that now my son is top priority, but what about all the crap that put up with? How can I build a healthy bond with my son if I don't feel any connection? I feel that I love him, he is my son after all. However, I cannot carry on through life with all of this anymore. Is this normal ?