Dear hurt and confused,
I'm also wondering if he had previously been diagnosed as Bipolar? If so, not being on the medications that he really needs to stay well would explain the out of character and irrational behaviour. I am married to a BP husband and I keep hearing everyone tell me not to listen to the things he says when he is not doing well, that it's the illness talking. It's the most difficult thing to do, but it may help you to know that.
I am very sorry to hear you are going thru such a rough time with him, and I can understand your emotional pain and sadness and confusion.
What is the likelihood that he will get back on his medications? Are his mother and sister not educated about this illness? I am curious because they are blaming you for everything, unless he is giving them that information.
One of the reasons this board is so amazingly comforting and helpful is because I truly don't think anyone I would choose to talk to about what we go thru (married to BP spouses) would understand, unless they were in that situation. Here, we can all talk objectively back and forth and help eachother understand, and in turn support one another. I have tried talking with my MIL because she is more like a neutral party, she cares about both of us, and she knows about her son's illness, and she knows how much I love her son. Although she means well, she still doesn't get it, she understand the illness, how it affects her son, or how it affects his family. All she ever says to me is..."well I just don't understand it, he was always such a sweet little boy"...geez.
Keep hope that the hospital stay may help your husband get back on track.