"Heartbroken" doesn't begin to cover it

Out of the blue, Hat has decided that he wants a divorce.  I am at a loss as to what to do.  I'm physically sick about it and I haven't eaten since he told me because I don't think I can keep it down.

I didn't notice anything was wrong.  We haven't been fighting.  We've been having a good summer together, going on trips and vacations.  I thought we were doing just fine.  But apparently not.  So, he wants a divorce now. 

In the process of this revelation, he has cut off everyone he knows.  He isn't really talking to his friends much, his dad has told me that he isn't responding to his dad's texts/phone calls, he disabled his facebook account because he "didn't want people to attack" him through facebook, etc., etc.  He also can't explain to me why he wants a divorce other than he's "not happy."  When I ask him what he means by that, he says he doesn't know.  When I asked him if he thought that a divorce would make him happy, he said he didn't know.  He also doesn't have any plan on what he wants to do after we separate--he doesn't know where he will live, how he will pay his bills (since I'm the one who is the financial support in the house at the moment while he's attending school), where he will get health insurance or car insurance, nothing...he hasn't thought about anything practical.  Everyone who knows him is having the same reaction, which is, "What?! This is so out of character for him!!"

The thing that makes this so much worse is that I asked him if we could try to work on it--couple counseling, etc, anything.  He said he didn't have the energy to try.  So, although we've only been married for a little over 2 years, he's just crapping out without even trying.  It's miserable. 

I can't stand how much this hurts.  It's the worse feeling I've ever had in my entire life.  I wish I could make it go away, even just for a few minutes.  I can't even get any relief from sleep--I keep having dreams about this situation!  It's a never ending horror.