How to be precisely supportive when your significant one has lost their mother?

20f here and 21m

I'm defying the subreddit rules but I need help.

I'm feeling devastated and shaky .

His mom expired today and he's just 21. I'm feeling miserable and i couldn't meet him today because I've immense anxiety attack plus strict household. ( Don't want to create unwanted drama)

So I will meet him for a short time tmrw. Idk what to tell and how to console him. Ik I cannot console him cz the loss is irreplaceable. I'm trying my best to provide love and affirmations through calls and texts..

Please suggest, what to do/ tell or what not do/tell? And how to Stop from breaking down myself ( I'm not sleeping since days and so on, loss of appetite , getting devastating dreams)?