I see your predicament JLT. It seems to me that you're already being supportive in the home by not drinking. Your husband used to be happy partying whilst he was drinking. Now he wants to stay at home and wants you there with him. I may be wrong, yet this seems more like your husband wanting control over what you do and who you see, than wanting support. He no longer attends these gatherings, so he wants you to stop too.
I agree, turning down all the parties would not be healthy for you. And you have every right to celebrate your best friend's 40th and attend your childrens school fund raiser.
You have the right to a life too...