Some other thoughts...
Sometimes parents have a really difficult time moving from relating to their children as kids, to relating to them as adults. The relationship changes drastically (or it should), and parents can often not deal too well with that.
Since your mother is showing an astounding lack of boundaries, you need to set some. She needs to be told very calmly, but in no uncertain terms (preferably when she's not having one of her hysterical fits), that it's not acceptable for her to speak to you like that. If she has a meltdown, leave the room (or the house). If she puts her hands on you, call the police (I don't care if she's your mother - you're an adult and nobody has a right to get physical with you). Feel that hard, knotty thing that runs down the middle of your back? It's called a spine.
If you don't stand up for yourself now, you are setting the stage for how people (and your parents in particular) are going to treat you for the rest of your life.