Thanks for your replies.
I have no desire to keep him from seeing Q ever again. I just need to come up with some sort of boundary or expectation which is reasonable before I can let her stay with him. If he wants to come visit while I am there, he can do that any time he wants. I would be happy to have him, as long as he is sober.
Our daughter is nine and I absolutely agree that what I did in the past does not make it okay for him to drink and do drugs when she is in his care now.
This is just so hard. Again, thanks for your replies and thanks for being there....