I hear ya, but u sound defeated. Don't let his problems become your problems. Dont let his issues define you. Figure out what you want and go for it!!
Ask yourself "Is he dragging you down?" Is he helping you become the best Mom/Daughter/Sister ect you can be. If not maybe your better off doing your own thing for awhile. Use the time you do have to do things for you.
With 4 kids it's most likely been awhile that you have taken care of you. This R sounds very Co-Dependent. You dont have to take care of your WAH. He needs to step up and take care of himself first.
I can tell from your post that you care more about taking care of your family more then yourself. This will eventually backfire when you burn yourself out. Make sure YOU are a priority!!