I'm glad your mom is doing better, Neil, my best wishes for her. I try to always disagree with you, just as a general policy, but even you occasionally says things which do not bear argument. Honor thy mother and father is a commandment for a reason - it's fvcking hard to do. If it was easy, it wouldn't be a commandment.
To the OP, your mother was abused; that's why she abuses you. That doesn't make it ok. The reason that this point is relevant is that, in probably just a few years, you are very likely to be a parent yourself. Or maybe you won't, and just be in a relationship. Either way, your mother's abuse has the chance to manifest itself again in your life by making you abusive to others. If she beat you as a kid, it's going to be hard for you to not beat your own wife or kid. That's the cycle.
On the bright side, abuse makes you tough. I know that from experience. You're not the only one who has these things happen with their family. A lot of us lived through similar hell growing up. Then you go out on your own and get away from it. And on thanksgiving and Christmas, everyone pretends none of it ever happened, and then you go back to ignoring each other for the rest of the year.