I agree with Beth. Meth addiction is a big deal. It is dangerous for you and it is dangerous for the children.
Move out now! Get yourself and you children to safety. Your husband needs to get into treatment... that is the only way that his meth use will stop.
When you move out, you probably are doing the best thing for your husband. An addict needs to be in a place where they need to make a decision. Meth is really bad news, it is a death sentence. The sooner he is at this place where he has to choose, the better chance that he will get over it.
Meth addictions only get worse. As his addiction progresses he will become a worse and worse husband and father. As the drug takes over he will become less responsible and more desperate and dangerous.
I would not consider being with him until he was doing well in a treatment program.