Advise please on a "blended family" We are on our last end

Mandi • Married in March ... Just found out pregnant in October
Thank you for reading. Let me start off by saying I am five months pregnant and I am happily married to my husband. I have eight-year-old son and my husband has a 11-year-old boy. I need advice on how to handle my stepson. He has a severe case of OCD he constantly is cleaning and organizing. he has to have everything his way he is very selfish and cares about nobody but himself every time he comes over everyone is miserable and he affects everyone negative around him constantly. Not only that he is very different just to explain his personality a little more he acts like a girl he has to act like a lala Loopsy's he has over 130 lala Loopsy is at his moms house she is an enabler. I get panic attacks I've almost passed out because he is too much to handle we want to take him to therapy and possibly put him on meds but the problem is during his divorce with his ex-wife he gave up soul custody and has no say in medical. Does anybody please know where I can go to get help in our situation we can't even trust him around my eight-year-old son and especially am scared of the newborn baby that is on its way. We have tried everything and our eyes we can only do so much because he goes back and forth from our house to his moms. His mom has made us the enemy and and gives him absolutely everything he wants no questions asked she never disciplines him she acts like his best friend. Plz advise on where to go thank you!