Christina,
Keep a journal of any evidence that you have that your X is endangering your child, actively drinking, disparaging you, etc. You want to be able to show the court why you are concerned. Even better would be for you to ask for a guardian ad litem another type of advocate for your child. The advocate would write reports for the court to let them know their neutral, professional opinion. This would also allow you to take the focus off of your X and to focus on your own relationship with your child and yourself. Ask your legal rep.
I am in the same boat with going to court and trying to get supervised visits for my 22 month old.
I also don't trust my X at all. I try to be open-minded, but mostly I just expect him to lie and keep drinking.
It might be good to limit your conversations to only things that have to do with your child. Your X will be angry, but you can learn not to engage with him when he gets that way.
Do you go to Al-Anon? Al-anon can help you learn how to respond in ways that are healthy for you.
Good luck and let us know how things unfold.