No Jillybird, "I feel terrible about it" is not the same as "I'm so terribly sorry for what I've done. I'm embarrassed about my behaviour and the trouble I've caused you. Please, can you forgive me?" I have to say that you're far more forgiving than I would be in those circumstances; he'd have been out on his ear on the first occurrence of showing disrespect in my home. Are you sure that you're up for this kind of behaviour? Is it worth it? Because it doesn't sound, from what you've said that he has much respect for you, your home, your generosity in allowing him to stay or even much self respect. I think I'd be reconsidering......
And as you've posted this in aibu...... no. You're not.