Honestly, the best solution is to just get the hell out of there as soon as you are able. In the meantime, here's one way to deal with your situation (not necessarily the best):
Don't expect your parents to understand.
Don't expect them to be kind.
Don't expect them to behave like mature adults.
Don't let your frustration show.
I can almost guarantee you that if you significantly lower your expectations, life with your folks will get easier. However, your mother might actually step up her game if she sees that she isn't getting to you. So be prepared for that.
I'm not very good at practicing what I preach at work, but I have to say that when I was eighteen, nineteen, and twenty, I had an easier time whenever I viewed my mother as an object of pity and as an obstacle to be avoided rather than as a person worthy of my attention and consideration. But take this with a grain of salt; I haven't corresponded with my mother, not even by letter, in a couple of decades. And I haven't seen her in person for the past thirty years.
It's quite possible that you will make progress by having a serious sit-down with your folks, but it really doesn't look like it. Then again, I have a rather jaundiced view of parents in general. For the short term, keeping your cool and playing your cards very close to the vest may be the best way to go.
