Does cutting all ties with my mom make me a bad person (sorry its long)?

My mom and I have always had a strained relationship. I grew up mostly living with my dad, because my mom beat on me and my brother. I tried so hard to have a relationship with her, but she always treated me like I was possibly the worst kid in the world. She always acted like I was a wild out of control teenager. I had a lot of issues with depression, self harm, and suicide. After a month of rehabilitation I began relapsing, and my mom flipped out and told me she had wished I had killed myself. She's always been incredibly selfish. I finally started having a fairly normal life when i was 19 and moved away. On my 21st birthday I found out I was pregnant. She was so mad, and then after a few months she was okay with it and we began developing a relationship. It was still very strained, but it was a relationship. After my son was born she drove 4 hrs to come visit. I drove up there a fee times as well, but everytime I tried to spend time with her, she would make other plans. She also showed no interest in my son...no affection..nothing. Then she started telling me how to raise him. She constantly criticized me. She acted like she was the perfect mother. Finally, I had enough when she told me I am a terrible mom and acting like a teenage brat again. Everyone knows I'm an awesome mom. I'm 23 yrs old and spend 24/7 taking care of my kid. He's my whole life. Does excluding her from my son and my life make me a bad person? She hasn't seen him since this past Christmas anyway...so does it really even matter?