There are many places that helps mothers in your situation get on there feet. i would call around during the day to see of the y can help you find a place you can afford. Tell them your full story they will help.
then if you can find a job during the day! if not then your gonna need a babysitter if the kids cant sit themselves.
After having all those things in place talk to your husband let him know how you feel. Tell him you and the kids may need to move until he get himself together. Check his reaction, most people on drugs have a hard time when they think there family may leave. --- thats why i told you sat all thoose things up before you spoke to him. you must remain 10 steps ahead of him.-----
Your parent s said you cant come home but they may watch the kids if they live close.
Lastly find a school for the kids in another distict if you can! Send the kids to there new school and pack there things they cant live without slowly.
Move -------Move ------- call your husband and let him know that you have moved and for him to stay intouch so yall can work things out! you dont want the children to witness any extra tension or fights if they dont have to!
Allow him to visit the children during the day at the mall or any other place where there are people. Even when you meet with him to be supportive dont let him know wher eyou live you keep control.'
Allow him to decide if he wants his family and if he does you two may be able to work it out if not you have a place getting help you can do this!
Use your resouces go to the welfare office in your city they normally know places that can help
I hope this helps