Wow,
Only you can answer that question, and it's so very hard. Because of the time and emotional investment. The best advice I can offer is to search the board and read the stories of woman that wish they could go back and change their minds when faced with the exact same situation as you. They have been through horrors up to physical abuse. It's even more worrisome that he has no job and no means of support, so in a sense you are an enabler for his addiction as well.
Tough spot, but at least you're in a spot to make a change. You wouldn't be here if you weren't concerned.