I guess you have to figure out where your support is, your friends and family, and ultimately your husband- and is it enough to keep you going ?
I do think of myself first now, it's up to me to keep my sanity. And if I do that then I hope I'm a better, or at least an easier person to live with as far as my family and friends are concerned. It might sound a perverse argument but I believe that to be the case.
Support is a two way deal, and I know my wife wouldn't be sat by me here if I didn't give something in return, if I didn't she would have crashed and burned a long time back. Or thrown me out on my arse !
I'v just re-read the earlier post from Babs, and I guess she says it all from a wife's perspective, I can see my wife there as well. As Bab's says, Goals, rules and frameworks need to be established- hey, we're going to break them alright- but they provide a kind of circle of protection for everyone involved, and when we break them and want to get back on track they're there, it doesn't matter what they are but for me our little rules are something to aim for, or something to cling to !!
Don't go under from sorting someone else out who ain't giving something worthwhile back, either to himself or you.
think hard- stay cool

Go confidently in the direction of your dreams! Live the life you've imagined. As you simplify your life, the laws of the universe will be simpler.
Henry David Thoreau