A man will seldom leave unless there is an OW waiting in the wings. It's guilt that's making your H leave everything for you, his comments about suicide, not letting his family know, etc. Just guilt.
Find a friend who can be your confidante --- someone you trust. That's what I did anyway. Just to get some release from the stress of it all. Don't go to family.
When does he intend to leave? It could be time to use the LRT. There are a lot of hints to what's bothering him in what he is saying. For instance, he says you are boring. Perhaps, he just feels he is bored with his life and it includes you and everything/everyone in it. Is there something you can do that will shake things up? Maybe being light and breezy justified his feeling of being bored. So, that didn't work --- what else can you try? How about dressing sexy and going out with some friends to a club? You need the break anyway, need to GAL, so why not try this. Make sure he sees what he will be missing. That's just an example, and I am sure you can come up with better ideas. Remember the time you first met --- what attracted him to you then?
Once he leaves for Montreal, there won't be much you can do (unless he realises on his own that it's not what he wants), so now is your time to show him that you are the greener grass.
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
Remember the time you first met --- what attracted him to you then?
