LO, {{{{{HUGS}}}}} to you. It must be very emotionally draining for you right now. Take care of yourself and take the time to be by yourself. Yes, it is his choice to file. Like others and your H said, he is still too confused. He is using this to get rid of his own pain. He thinks by filing, the pain will go away because all he now has to do is follow the paperwork. It is his choice but you have your own choice. Detach and be a great person/mother, without H. Don't give up yet.
Brace yourself for more rollercoaster ride. I am sure you already guess your H will still flip flop. He can do all the flipflopping as he wants. You can be the constant here, a great person, a great mom. H will see that. If he does not, or he does not appreciate, that's his loss. You will be a better person for all others.