Listen to yourself....
His RULES? like he owns you?
Isolating you is not good, you should be able to make these decisions for yourself, who you visit, communicate, get support from.
He is the sick one, in rehab...a controlled protected environment. You are out in the real world, dealing with the kids, bills and the aftermath of the financial destruction he left for you.
I would be more than resentful, I would be livid, the hell with his *rules*, do you see how silly this is?. He is still trying to control YOU, but he can't control himself.
the last thing you need is to have contact with him on a daily basis. you need a break. You are not supposed to "tell anyone", WHY???? He is the one who is in rehab, not you.