Depressed found out childs father on drugs

Hello everyone so I am currently 24 weeks jus found out my childs father has a drug addiction to pills and weed. I previously knew about the weed but didn't know pills were involved until he started running through his checks with nothing to show and asking me for money knowing im out of work on bed rest because I'm high risk. The other day we got into it because I told him I was taking the baby and leave he hasn't bought anything for out child and he knew I was pregnant since October I've been giving him time to get his self together and telling him I will go with him to get help which is rehab he claims he can stop on his own which I don't believe. this last past time we were into it he allowed his pit bull to attack me in the middle of a heated argument between us too I suffered from multiple dog bites and not once did he get the dog off of me I ran an packed my things and left. I had to go to the hospital and everything is okay with the baby but I was really sore and barley able to walk for a couple days. (Update) now he is texting my phone saying I took his child away and he wants to be in his childs life , honestly I dont feel safe during our argument that day he also mentioned he wanted me to miss carry and laughed and then said sike I'm just playing I find nothing funny about that I recently had to get surgery on my cervix so that I am to go full term so for him to say that about his own child broke my heart. Im now home with my mom but ass him being my childs father I'm still concerned about him I don't want him to self destruct and also I feel for my son that he got to grow up in this broken home but this is what's best I do plan on going to the court for full custody because I dont want my baby expose to any drug use please give my positive feed back have anyone been through this.? What would you guys do in my situation.?