I have no experience personally with this but from what I hear it is good if you document when and where past occurrences happened. The more documentation you have, the better your odds of having visitation restricted, supervised or cancelled completely until a decent period of sobriety can be "proven".
It would be a good idea to get a lawyer involved to protect you, your child and your rights.
It frightens me to think of young children in the care of an active addict or alcoholic who cannot be responsible for themselves, let alone anyone else.
Good luck, you are in my prayers.
Hugs