I am so sorry.
I have to tell you, this past April, my sister in law called me BAWLING! My brother rolled over one morning, said he wasn't happy, didn't want to be married, have kids, etc. And left. Here she was stranded with a 6yo, a 2 yo and pregnant.
I called my brother, and he was adament they were not getting back together. He said that he was having some rough times (emotionally, getting older, gaining new responsbilities, etc).
A week later they were back together. He needed time away, I guess. Guys don't do things as rationally as they should. I told him that the next time he needs "time away", he needs to tell her that, and check himself into a hotel...not just up and leave and say he is never coming back.
I hope that is all your husband is doing - needing time to himself. Maybe you guys go on the trip...let him have his time alone (as selfish as it is!), and see what happens when you get back.