I went through this battle....stupidly I have gone back and wish I hadn't but I have gone through the battle you are going through...only thing is I didn't do drugs but he did.
Let me start off by saying....get the best darn attorney you can. Mine cost me about $6000 but it paid off at the time. I got it so that not only did we get supervised visits in the beginning but after a while he had no visitation rights at all until he submitted to a drug test..which he never did.
Not only that, get documentation from your doctor that you are on medication and what it is for.
Go to counseling for this problem going on right now so that if you have to go to court it is all documented for the judge to see.
If he ever lays a hand on you call the police! You don't have to have him arrested but you can file a report and that will be on file and you will have a copy .
Start a notebook with dates and times and write down everything that happens, the threats he makes alone are enough for supervised visits because he is a flight risk and he has issues with his anger verbally. They are also good because you can get him for terroristic threats...yes him threatening to harm you, your child, your family members is terroristic threats and you can get a restraining order once you start the court proceedings for that as well.
I hope this helps...if I could get through it when I did I know you can!