Congrats! I used to be in a similar line of work at a residential school for behaviorially challenged kids/teens, and I worked on the special-needs unit. I used to call them my "kid tackling" days.
The physical requirements can be kind of overwhelming, and I remember for a long time, my mother was grateful I was overweight with a larger frame because it meant (in her mind) I was less-likely to be a target for aggression, and in physical management, someone would have a more difficult time bucking me. Boy was she wrong.
It definitely takes a lot of strength, both physically and mentally to work in that type of position. I give you huge kudos. Congrats on your progress!
On a sidenote, I no longer demonstrate for anyone not in the field the physical management techniques I used to have to employ. A few years back I was showing a friend a hair-pull release technique. He was too big of a guy, and while I wasn't trying to control him, he stepped back into me, popped my knee and we both tumbled. He rolled across my knee and I ended up in the ER with emergency surgery to remove a bloodclot the size of a small fist from the side of my knee.