Do you have family/friends who will take you in until you can get on your feet? Find a support structure and reach out to them. If you don’t have access to that, find a shelter for abused spouses or a church. (My mother and I took in an abused woman for a year upon request of our priest. I still think of that lady fondly. She was like a grandmother to me.)
You are probably eligible for at least food stamps, possibly some sort of government assistance. Your child should be eligible for state-sponsored health insurance. Apply for these as soon as you get away. I don’t know if you have a degree or training in a skill, but there are scholarships and grants which could help you obtain education that would improve your and your child’s lives. Some schools will let you train at home or at the library, if they have a computer setup. Look into this too.
I know this is a horrible place in your life right now, but do your best to think of it as an opportunity. Life can get better and it will. It won’t be easy for you, but don’t be afraid to reach out to those who can help you. If you can get far away from your STBX, I would to ease the chaos that surrounds divorcing an addict.
I know what I’m talking about here. I was younger than your daughter when my parents separated. My father too was an addict. Neither parent had a job and we had no food or running water. (We had been eating 1 meal or less per day for several weeks.) My mother called family who drove several states away to come get us. It was the best decision she ever made. We stayed with them for 9 months until we were able to move out.
To be sure, there were some rough times emotionally for me in the first 3 months before my dad accepted that my mother wanted out, but the good outweighed the bad. In the end, it was beneficial for everyone. My father finally got treatment, my mother was happier than she had ever been, and I always had a roof over my head and food on the table for the first time in my life. My parents cooperated with each other to raise me and never competed with each other or said anything bad about the other. In the end, they respected each other’s future spouses and worked with them for the good of everyone.
This is a hard step for you, but my prayers are with you. Good luck and keep us posted. You are doing the right thing.