Bad relationship with mom and want cut her out of my life?

I was adopted because my parents can't have children. I grow up in China and had a horrible childhood. My parents were very controlling and emotionally, verbally abusive for as long as I can remember. My dad ped away, unfortunately I don't miss him and still have nightmares about his abusive ways. Now I am married and live in USA. I bought a house for my mom in China and she is living with her new husband. I never felt she is appreciated for what I did . I seldom visit her, because everytime I do, she never fail to make me feel miserable. Last time I visited her with my husband, she was mad and yelled at me because we were out with my old friends and did not come home at 10pm. she said we were disturbing her from sleeping since she had to open the door for us. I am 41 yrs old and seldom visit her! The truth is, I really don't like her, even talking to her on the phone or thinking of her makes me depressed and reminds me of my bad childhood. I don't want to see her or even call her, I want to cut her out of my life completely, but feel like is an obligation since she is my mom. What should I do?