Aaww Jjulia, hope it all goes well!
Have you discussed the weed problem with your son?
I bet he doesn't want to do that stuff if it makes him delusional.
Do his friends know that he gets them when he smokes pot?
It would be good if he could explain it to them when they offer him some. Hopefully they are open-minded and not freaked out by that kind of stuff.

Ah, don't have much advice, I just hope it all turns out well. Much strength!