HI Tim; A diagnosois of cancer is a pretty scary thing and is bound to leave you feeling somewhat anxious and helpless. Your whole life (and sometimes death) just passes before your eyes. It takes a bit of time to get that confidence back...believing that you have another crack at life.
I would be thrilled to bits to have received your good news and had your experience through my treatments instead of the more dismal time and tale I carry.
Sounds like you have had great treatment and good news...choose to believe it, and go easy on yourself for the anxiety..it's quite normal and also responds very well to small doses of anti-anxiety medication. It's worth the good night's sleep and the peace of mind you'll have. Ask the doc, I'm sure he'll prescribe something to help you by this rough spot.
All the best,
Fran