He is typically a great dad and one of the funniest and kindest people I know. I hated thinking that he potentially had this in him.

The parent-child dynamic is complete different than a marriage dynamic. One can be a great parent, but a lousy spouse. Your mom has no authority to unilaterally kick him out as he is on the mortgage etc. If they get a divorce then assets will need to be split and there is a good chance that the house would be sold in that event and she will probably get some alimony from him.

Don't confront him right now. I get that you are angry, but don't burn any bridges with him. I am telling you that for your own good because this is an issue for both of your parents to be handling. You need to focus on yourself and your own health right now.