I have to tell you that I had the same kind of relationship with my mother for many years. Finally I had had enough and I went to a local priest and asked him if it was okay that I didn't like my mother. He told me that it was okay not to like the person she was. (I was religious at that time)
I cut all ties with her for 4 years. We began to talk again, things got better and she became my best friend. I lost my mother in 1994. I miss her every single day of my life.
My mother was NEVER married, had 10 children by all kinds of different men, we grew up on welfare, she was an alcoholic, we were horribly abused, she pushed me down the stairs and broke both my wrists and I could go on and on here.
Push her away or step away. Leave it in your heart to possibly mend fences in the future. It may not be possible but then again, it may be like what happened with me, and you may find your best friend in your mother.
Good luck hun.
Laurie