I understand your situation completely because I had the same kinds of issues with my teen. I don't understand why you can't get support from a therapist if you have documented your teen's behavior and if your husband backs up what you say.
I will tell you that my teen was admitted to a facility and came home and his behavior reverted because the home and us, his parents, were triggers for his old behaviors. At the end of our rope, we tried this program called Total Transformation which is made for teens who are oppositional, defiant, disrespectful and just plain cruel.
Going through this program help us to make a serious intervention at home.
We worked on our son's behavior as a family and even though I was skeptical at first, it actually worked. Not only has our son turned around, we have actually become close. Going through this program meant that we had to change our behavior too because we learned how in many ways, we were enabling him. It was shocking to me at first because I thought I'd done everything in my power to help. I have to tell you that it's great to live in a home where we're no longer frightened of our kid's behavior. That's how scary it was.
Even if you get your kid into a facility, I recommend that you go through this program because eventually, he's going to come home again and you are going to have to know how to deal with him. No matter how much progress he makes in a facility, coming home and being around his parents will bring up some of his old stuff.
I wish you the best of luck. I know how hard this is, but you're doing the most important thing which is taking action.