Love is just an emotion and sadly, with your declaring you love him too much to expect being treated well, you'll end up mistreated as you are now,. good luck
Oh goodness. Well, this is a rough one dear. I'm afraid you caught him in some kind of affair. He's not just flirting. He basically is either physically involved with her or emotionally when he says he can't hurt her. That means he has feelings for her. Where does that leave you?
I'm worried that you are so focused on getting him back when he has done you wrong. The appropriate response is anger. Do you mean you can't live with him because you need him financially? I'm not sure I fully understand.