Hi Sadie.I am so sorry for what brings you here but glad you found us. This is a great place for support but also to learn how to take care of ourselves as loved ones of an addict.
Have you read the stickies at the top? They are full of great wisdom and information.
As for your husband there is nothing you can do to stop him. He has to want to change.
Right now you need to do what is best for you and the children. Are you afraid of him using all your money for drugs? That may be something you need to take care of.
I would also recommend reading Codependent No More by Melanie Beattie and seeing a therapist if possible.
Others will be along shortly with support and help. I'll be saying prayers for you and your family.