Reading your post brings back painful and still vivid memories. Please know that I understand and wish there was a way to send comfort via this post.
I'm quite sure you were not around when my grandson turned his apparently near perfect life into a nightmare that has lasted for years. It was so shocking and so unexpected and I really couldn't accept that it had been his choice.
BUT...it was his choice. Going to Court and having arrogant Prosecutors seeking maximum incarceration etc. was a huge shock. I had not realized what an adversarial legal system we had!
on the other hand, exhale and be thankful that he did not get to prison. Even though they "sort" prisoners before assigning them to facilities many of difficult child#1's "friends" have been molded into criminal behaviors via incarceration. Personally I know two young men who were sent to boot camp. They both survived and one came out a much better person. That boy had never been into physical activity, he was far more passive than he was aggressive...and he thrived in the structure and in his personal development. Obviously it can go either way for your son. If he can "man up" for the experience there is a chance he may be ready to move on toward adulthood.
Meanwhile I "know" your pain and I also know that you have an opportunity to catch up on your rest, relearn the joys of not dreading a phone call or a knock on your door, try to find something "fun" to do. Don't serve his sentence with him, my friend. That won't help him and it surely won't help you. It's time for him to chart his future...you, too.
Hugs. DDD