Hi Chel! So sorry you're having such a bad time. I know how one's feelings can get hurt, where your stomach hurts, your heart beats painfully, and you just don't know what to do. Been there, done that, got the coffee mug.
Look, I did get my H back to a degree, but it's not the person I married. It's more like the best friend came back, but the H didn't. And, I think it was because I was too easy on him. Perhaps if I had been harder, stronger, less willing to accommodate him and his needs at that time ('cause now, none of my needs are being met except those of a friend).
So, here is my advice (and I am going according to my experience ---- your H may react differently) ---- tell him to go to Montreal, do whatever he wants, but you are going to take your time with the D no matter what he does. The papers can be sent there. Tell him he is a damned coward for not telling his family and quite frankly you are not interested him anymore as a husband (since he's not the same man you married), but you are still going to take your time, because this is not something one rushes. You will require at least 6 months (or whatever time you think is best) to settle things with your attorney's assistance. If that doesn't fit in with his schedule then tough luck. You aren't here to wipe his feet on. Also, tell him that if he does go to Montreal and bites into any new flesh, then there will be no coming back ('cause you don't know what disease he would pick up), no friendship coming from you 'cause a friend doesn't cause this sort of pain.
Anyway, what I am trying to say here is you have to toughen up, don't let him see you cry, don't give in to his anger and manipulations, his little tantrums. Decide on what you're going to do and stay the course. I get the feeling that your H has had his way most of your M which is fine if it's benign and you're happy, but now is not the time to let him pout and you go, "aw, I'm sorry, okay I'll do it." Tough love, I think is what it's called.
Take care.
Me:57 H:52 M:28 Got another lawyer last year and filed. D35,S/D twins28,D22 EA4/04 End? Who knows? "Life is like a mirror. Smile at it and it smiles back at you." — Peace Pilgrim