Ugh.. I totally feel your pain. This is something that I too have struggled with. I am 22 and my mother had taken advantage of me, stolen from my husband and I, and done everything else you could imagine. I tried very hard to repair my relationship with her and forget the past. I eventually came to the realization that she would never change. I now have not spoken to my mother in over 2 years, and I am very happy with my decision. I was able to allow myself to forgive her, and move on with my life.
Some of my siblings are still under my mothers wrath and have tried over the past 2 years to coax me into having a relationship her, which has caused me to have to end relationships with them as well. Overall, I am very happy with the decision I made and I am thankful my husband has a great family that accepts me.
I went through hell with my mother since I was 14 years old. There came a point when I realized that by having a relationship with her, even though I thought I was trying to help her, was enabling her to ruin her life and mine. Just because someone is a member of your "family" does not give them the right to emotionally abuse you, nor does it mean you have to put up with it. You have to do what is going to make you happy and increase your quality of life. I will be praying for you