Honestly? I'd just go, myself, right now, and get some legal proceedings going so you can make a real plan with some notion of what you have to work with. A protective order is one option. You have photos of the bruises. While you should not have slapped him, from what I gather, his response was out of all proportion. Even if you don't go that route, a lawyer can advise you whether you would be entitled to pendente lite support (pending divorce). Presumably you have income from your renter, so you aren't penniless.
And honeypig is right--even if you get him to feel guilty enough in the moment to agree to move out, that could change at any time and you still have no long-term plan or security. I'd suggest making a plan for complete self-sufficiency.