Anger is not too unusual when dealing with ADHD/ADD. There's a lot of frustration and anxiety that comes with the territory. And that frustration/anxiety may come out in the form of anger for you. So, it's very important that you learn another way of dealing with it.
Anger usually only pushes people away. It's not the way to get support. And that is why you are going to this facility, afterall, isn't it?
So, perhaps you may want to get some anger management help.That act would show them your willingness to work *with* them and end the threat of throwing you out. Furthermore, as you can see, your anger is not helping your situation. It *may* have hurt other situations too. (I do not know this, but, it is something for you to think about.)
I sincerely hope that this suggestion is helpful to you.
Peace!