Cathymac first if all sending the biggest hugs to you.
Are you able to contact any of his mentors or his counsellors?
Im not sure but there maybe a support group for siblings that have a family member with cancer you maybe able to tap into.
Not sure how old your youngest son is but you maybe able to access Camp quality
https://audifoundation.com.au ;
Cancer support for affected offspring Can Teen Australia
https://www.canteen.org.auMaybe talking to other kids around his age going through the same difficult time may help, knowing that what he is feeling is normal.
Im sure some other lovely ladies will be in touch shortly with their recommendations, this is all so new to me aswell at the moment.
This BC just sucks it affects everyone, I’m feeling for you so much at the moment.
Do you have a breast cancer nurse nurse you can reach out to? They are full of information and have resources in your particular area.
I know you can have access to a Breast cancer retreat through the OTIS Foundation. otisfoundation.org.au
Just a few days away with the family may help, I know it’s not your trip to Europe, maybe a few days away might help.
I know it doesn’t stop you worrying, at least he has made contact.
Just reaching out and giving you a massive hug ❤️