oh wow RedHeadedsuzie...I didn't realize that you hold all the cards! This changes this drastically (somehow I thought you were unemployed and that he paid for everything). So really, it's just a question of shifting your perspective here:
You're taking steps to care for your physical and mental health, despite the difficult times you've been through.
Your kids are in college so you don't have to worry about protecting little kids from the alkie
You have a good career
You have support from your family
Perhaps all that's needed now is shed some dead weight
And maybe some counselling to get some much needed support?
Have you considered consulting a lawyer and seeing what your options are with regards to separation? It never hurts to get informed...