Hello mango
I’ve just gone through the same thing and I must admit the waiting was by far the worst period.
As for coping I found this site,reading peoples experiences and trying to hold on to whatever positives you can.
He is young and I presume no crab symptoms so lots of positives.
I’ve not started treatment yet but have had diagnosis confirmed.
All I can do is offer heartfelt support and best wishes.
Andrew.