The first time my son went inpatient, he got worse for a few days before he started getting better. It was involuntary & he tried to escape, so maybe it was the shock of it.
You have no idea what's going on in his head, and I've been told it's common for people to not call or accept visits at first. I know it will be hard, but don't try to guess if he's met someone else or if he's mad or wants a divorce or what. In fact, I wouldn't take too much of what he says to heart when he's sick.
I've been married for 28 years. I used to freak out at every single thing that happened & think it was going to be the end of the relationship. Looking back, I think my husband may have been mildly bipolar (it runs in the family) or had something else going on that he seems to have aged out of.
Basically, my husband always thought I was cheating on him no matter what I did or didn't do. And, it's pretty hard to prove that you didn't do something. Otherwise, he was OK. The problem was I never knew when he would go on some kind of rant. Now, I know it was probably delusional disorder, but at the time I thought it was just from trauma while he was growing up & the fact that pretty much everyone he knew from his mother to his sister to his friends slept around.
It all suddenly ended like someone flipped a switch in his mid 40's, but I feel like it robbed me of something and I can still be a little bitter about it. If I had to go back and live my life over again, I wonder if I would have still even wanted to meet him. He's a great person in most ways, and he was truly the love of my life, but were the good times worth the bad? It's hard to say. Some days, I think I would have still done it - other times, I think I wouldn't.
My original point was that after about 7/8 years, I had a moment where I realized that if we did split up, it wouldn't be the end of the world. We both had a life before the marriage, and we could both have a life after the marriage. It was a liberating thought and a very healthy thing for me.
If you choose to stay with your husband, it will be like any other marriage. There will be good times and there will be bad times, but you have to decide if you are strong enough to weather more times like these if he won't stay in treatment. If you're enabling him in any way, and that's an easy thing to do, the marriage might not be healthy for either of you.
While he's in the hospital and not ready to talk to you, maybe it would help if you saw a therapist to discuss both his illness and your marriage?
If you want to call to check on him, you'll probably have to go through the nurse's station. You can always check to see how he's doing without speaking to him. I don't think it's weak at all to want to call. Maybe he's not calling because he thinks you don't want to talk to him?
If I wanted to call, I'd call - I wouldn't worry about him being nasty or some other girl.