Your self confidence has taken a knocking, because of what he's done. You doubt yourself, you doubt your own judgement, because some one you love and trust has lied and let you down. I get that, I was like that.
Your confidence will grow, you'll get back to your old assertive self.
Everything you feel is natural, but trust yourself and be strong. You are your own best friend. Fast forward ten, twenty years, imagine your daughter in a marriage like yours. Visualise it, would you think it was ok, that she should put up with it?. I bet you'd move heaven and earth to support her, to help her leave, I know I would. So do it now for yourself.
You are worth so much more, lead by example, show your kids to have standards, to expect the best, and not to think being treated like you currently are, is acceptable.
I think you're doing well. When you see him, you'll get a lot of empty words, promises etc., see them for what they are, him trying to keep the life he has with you, and his secret life with OW.
Most of all, be proactive, not reactive.
I wish you well x