I ditto the "sometimes I think they deserve so much better" comment. I have felt that a lot. I never felt like I was a good enough mother - even for the brief few months that I wasn't extremely depressed.
But then I try to remember - I am working on fixing myself. And I'm doing the best I can to give her the best life possible.
I have never, and will never, hurt her. There are no drugs or alcohol in our home. She has a loving father who plays with her every day. I provide her with a safe and clean home. I'm doing the best that I can. I tell her I love her EVERY day, and I hug her at least 2 or 3 times a day.
It's like my mom's cancer. Sure, I could just accept the fact that my mom had breast cancer so that means I'll get it. And truthfully, I still might. But that doesn't mean I can't eat healthy, lose weight, avoid hormone therapy, and take other measures to decrease my risk. Sure, the risk of me getting cancer will always be there. But I can do everything in my power to reduce that risk.
Sure, your kids may risk inheriting some of your traits. But you can try to do everything in your power to prevent that - even just telling them you love them, and refusing to allow them to be abused, that alone can help stop the cycle.