20 weeks and getting divorced?

I’m 20 weeks pregnant and so far have had a very rough pregnancy, I’m extremely ill and continue to loose weight. To top it off my husband has been very cold distant and seems uninterested in life in general. This morning I could tell something was really bothering him so I ask what’s wrong. All he says is this relationship is dead and there’s only one thing to do. . . a divorce. He then walksaway! I mean therapy isn’t an option? What do I do I’m half way through this pregnancy and about to be divorced with a 7 year old and 1 on the way?