Most families have someone in their life that causes pain. I know I do and what I have done is to just cut ties. The back and forth the crazyness is just too harmful to me and I stopped seeing this person 15 years ago.
They have their own demons for sure, something happened to them in their life to make them this way, many things in fact.
But there comes a time when you have to move away to save yourself and I did that.
Not having the love and support of a parent is always tough and extremely painful BUT having a parent continue to do harm to you and your family is worst.
Wishing you the best of luck. Enjoy the wedding and look to the future not the past.