I have cancer - can I donate blood/plasma?

I currently have thyroid cancer - had it first in 2008, having a recurrence now. I had surgery in April and am scheduled for radioactive iodine treatment in August. Right now I'm looking for work and am super low on cash so I was looking into selling my plasma and/or blood but I don't know if I can since I'm technically in the middle of cancer treatment. An answer from someone with some medical knowledge would be great.