You don't sound selfish at all. Your mother sounds sort of unpredictable and negative. I agree that spending less time on the phone with her may be a good idea. Hanging up on her when she becomes abusive or says rude things about your plans is also an option.

You probably can't make your mother feel better when it comes down to it, no matter what you say. It's not your job. It's her job. I hope you can get back to speaking terms before the holidays, but don't feel guilty about this. She sounds a bit manipulative.