Personally i think db the hell out of him.

Are you ready to file? Is it an emotional decision? A rational one? Is it to scare him into coming back?

He is a mess of a human being, whi has treated you so so poorly. Let him stay where he is, im not sure it would be a healthy situation for you and the kids if he came back now!

You are right it seemed that you were just finding your feet and getting to a healthier place where you started to value yourself. Do not have any expectations, please read what May said about all the things he said and did!
He is telling you now about his relationship with another woman! He wants to gove it a go because he has invested 3 months into this?!

It was a hard no for me from very early on hearing about OW! I told H out right that woman doesnt exist in my life, keep your personal life as far from me as possible.