I agree with Sara. My experience with kids who suffer with disorders like ours is that nothing is a one step fix. Putting him out of the house will not teach him a lesson or help him into adulthood. If he is anything like my child, he would be curled up in a fetal position under a bridge.
One medicine doesn't turn the tide,
One therapy doesn't bring an immense light bulb going on.
It's trying to look at the world from their shoes and understanding why they think like they think. Because I'm the parent and I have the sacred responsibility to help this child to adulthood I have to work on helping difficult child find his way out of the dark box they pull themselves into when they feel a need to protect themselves.
I understand that you are all alone with an aggressive, scary adolescent. I understand that you want some supports. You need a safe place and a circle of adults who will come when you are in need. Neighbors,church members, family members or something like that. Calling police is always an option.
Have you connected with any of those organizations for parents of children with mental illness? There may be a chance of making connections for services. I asked everyone I came across for information.
I had a heck of a time in Texas trying to find services through the public system. I have found it easier in NC. Wish I could give you more suggestions. We are on the waiting list for adult supportive living list(it wasn't even a great fit but it was the best I could go with)for 7 yrs. HS counselor suggested it and they check every year to see if we are still interested.
Have you looked into the group
PLAN in Richardson. My difficult child was under their umbrella for a year. It may be an option in terms of him living outside the house.