Dear Sara,

You have to talk to him and tell him how you feel.
We tend to vent our anger at the ones we love the most. He may be pushing you away in an attempt to go it alone thinking it won't hurt you as much if the worst comes to pass. A big mistake on his part. This is a time when he needs to share with you how he feels deep down. It is a scary situation he is facing and may not know how to handle it.

I agree with Mark he needs a reality check big time. New medication and a psychiatrist in dealing with severe depression should be concidered.
I hope and pray that he wakes up and realizes you are his most important and loving supporter.

All my Best, Danny Boy