I have been following your story because your ex sounds a lot like mine and this is heartbreaking. I do not know where you live and it seems the court situation there is really screwed up. If CPS has been involved, can you not take him back to court on an emergent basis for full custody? Again, I don't know where you are and I am not an attorney I just know in my case when I have felt my child is unsafe (and him refusing to feed your child is child abuse, additionally verbal abuse calling her a brat) I would personally withhold the visitation document subpoena everyone i know who has been involved including CPS and plead my case in front of a judge. In my experience no court order or agreement is final, it can be brought back in front of a judge due to change of circumstance. Does your state not have this? This abusive psychotic behavior hes showing seems to be worth that, if at all possible. And, I agree with Lexie you should make an appointment with the DA directly to talk about whats going on here.
Honestly my heart breaks for you and I will keep you and your family in my prayers.