Hi CB! Well, I have found myself in a similar situation w/my own DS. He has had a kidney transplant and is immunosuppressant, which means.... He catches everything. I try to be the overprotective Mom, always have been.... BUT.... my DH takes me aside and gently tells me to take a step back and let him live.
I've been doing this for 29 yrs, as he was very ill at birth. Plus, he is almost blind.. So....

I can relate to how scared you are. Our children are our lives...My DS runs his own business and is around germs, bugs all the time. I stress about it so much.

Just last Sat, we were in the ER clinic, as a drippy nose turned into bronchitis overnight. He is really sick right now, but is at work!!!

Yup, being a parent is the hardest job I've ever had, but the most rewarding. I understand your fear for your son. I live it every day, but I also "try" to understand that he needs to do his thing.

I will keep your son and you in my prayers and DO keep us posted on how he's doing. Chemo is tough stuff... Sending hugs to you...