You are not a fool. You are not an idiot. You are a good mother and an abandoned wife making extremely difficult life decisions in an unstable and terrifying situation.
The reason for avoiding any attempt to have a normal conversation with him is that his brain is obsessed with drug-seeking, every minute, every day. That's what it wants. Normal conversation with that brain will not happen. That brain has other plans.
He may badger you because--unconsciously--his brain is setting up yet another reason to drug. Addicts create stress because stress triggers using.
You love him. You want him back. You want a husband and a father for your children. Your desires are normal.
And the best thing that can happen to him which offers him a chance to be that man again, some day, is a hard bottom.
Stepping away allows him to experience every painful consequence of drugging (absence of wife, absence of children, absence of home, absence of dignity). Then he has a chance for a hard bottom. If he thinks he has normal marriage problems because he's a normal guy with a confused wife.....he'll never see the real problem.
So just read some books to your babies, tuck them in tight, and let him stay out there feeling all the pain of life as a drug addict. Some good can come of that.