Regarding medication: Liquid form will help; also put any crushed pills in honey; that works wonders and I’ve done it before when I was younger and couldn’t stand larger pills. With capsule adderall it’s the same way. Best and sweetest way to disguise taste!
Regarding sleeping at night: One of the things that helped me as a kid was having stuffed plushies, sometimes big stuffed plushies with me since I never let the family pets sleep with me (I still do it I’m a grown woman with giant orca plushies, despite having a cat now). So, when he starts sleeping on his own he’ll have a big friend to sleep with. Also, one of the best ways I found on my own no less when I was a kid to reduce anxiety at night is to cover with a heavy blanket or put something over your head. A pillow, a blanket, whatever. It helps muffle sounds and gives that comfort feeling.
Not sure about the child’s body thing. Yikes. It definitely sounds like he’s got a lot of anxiety issues, worse when you have adderall in your system. It might be a good idea to just test and see what works best for him and to articulate with him what helps or doesn’t help.