The only thing you can do is cut off contact with her as much as possible. If you loves you, she might try to act nicer around you to keep you around. If not, then is she really worth all the stress and anger - even if she is your mother?
Does she forget and confuse other things? It may be time for a thorough checkup.
If you already knew she liked to just be mean, why do you still listen? I mean you can't change people so all you can do is learn to just block her out.