I was the primary wage earner in our family too.
I hate to even think about how much of my hard earned money went to the heroin dealer before I wised up and opened my own account. I'm pretty sure that I could have taken several extended trips to Hawaii or Europe with that dough!!! Or maybe even paid for several years of college tuition for our son. Once its gone..its gone...Ugh...
If the addict is going to use drugs...they ought to at least use their own money for it. Don't make it easy for him to use. Money intended for your living expenses should NOT go towards his habit and really...the only way to prevent this from happening is to be proactive and protect your bank account. Like Done said, the addict doesn't see see or understand that they are taking the very money needed to care for their family. Its hard to understand but oh so true.
You are one smart cookie!! Your kids are lucky to have one stable, responsible parent in their life.
Good for you!!!