Hello Justshy, I'm sorry you are in such pain. It is a shame that they just showed up like that. If you had been given any notice, you might have been able to make arrangements to be elsewhere at the time.
I agree that his 'Mommy' is getting a bit too involved, but he is allowing that to happen, and there is nothing you can do about that.
I know this hurts. It hurt when my first husband moved out to be with his girlfriend and filed for divorce. I, too, just wanted to talk to him, to get some sort of resolution. I suppose, though, what I really wanted to do was to talk him out of what he was doing. Sadly, that never would have worked, and I would have given away every last shred of my self esteem in begging him to stay.
I know how much all of this hurts. I understand how hard it is to not have a resolution and the answers you want 'right now'! Unfortunately, life just does not work that way.
Your husband has made the decision to move out. He has signed a 1-year lease. Those things are facts and there is nothing, and I mean nothing, you can do about it. A year is a long time, and much may happen in the meantime.
I hope that you will take the time over the next year to become the best you that you can be. If that requires counseling, then I think it would be well worth it. You deserve to be centered and happy, and your children deserve a happy and healthy Mom!
Maybe do something just for you this evening--I know that sounds trite, but popcorn and a few home improvement shows on HGTV usually improve my mood quite a bit. I hope that you will try to get some rest tonight, too. If I'm sleep deprived, the whole world seems depressing to me.
Please take good care of yourself and those precious children!