Lila I have every sympathy. Try to remember, and I know this is hard, but folk with MH issues are NOT thinking in the same way as we are. It's not as easy as saying that they have to want to get better. Of course they want to get better, but they are not thinking in a normal manner. DH says that, when he's down, he find it hard to process simple instruction. MH is an illness, like cancer, or heart disease or, to some extent, Asperger's (a condition, anyway).
I don't know why your DH lied. It may be that is WAS a selfish, thoughtless act. It may not be. And you won't be able to talk or find out until he is functioning normally again.
Unless you live with someone with MH issues, you really don't know, you honestly don't, I promise.
The key is to ensure that you have support outside of the immediate family structure, or to be able to take a break yourself, or some one who you can unburden to. Anger and resentment and exhaustion are all normal, I promise.
I do understand, DH has been diagnosed bi-polar for 7/8 years now, but was ill long before this. He will ALWAYS be bi-polar, so we will always have to live with it.
Take care 