It sounds a lot like avoiding, which can be a result of anxiety.
I suffered severe anxiety & depression a few years back & had some similar experience. I was constantly calling in sick to work, sleeping all day, stopped eating, struggled to shower & brush teeth every day & usual daily activities became terrifying. I couldn’t even make a call or book an appointment without intense anxiety. It made me shake, racing heart, struggled to breath etc.
So I avoided everything by staying in my room. I also felt intense shame about my struggle to work, my hygiene, the condition of the house, the lack of courage to ask for help.
im not sure if your some is in a similar situation or there is something else going on, but let him know you are there for support, ready to help if he needs it. That’s what I found I needed most. I needed to not be judged, just to be listened to & believed.
I hope things can improve for you & your son. Good luck