Hugs, Tryintosmile. It certainly seems overwhelming when looking at the entire picture. Making a "To Do" list and looking at just the next item is so helpful in making it feel do-able.
Contacting a domestic violence resource can help you figure out how to get away safely - or if there are options to get him away - and they can help you make a safety plan - they're not necessarily the same thing. They can help you get a protective order against him. They can point you to family law lawyers. I think it's important to note here, that they won't make you do any of this. If you're not ready to take a certain step, they'll support you with your decision and help you with other aspects of staying safe.
Please do listen to your instincts. You know what he's like and what asking him to leave vs. you leaving would play out like. But you don't have to do this alone. And as great and as supportive as your Mom is, you may need more help to stay safe.
Stay safe. Wishing you peace and continued strength.