Strange symptoms after head CT?

I’m not sure if these are related to my head CT, but since I’ve had it done (about 3 weeks ago), I’ve been experiencing moderate to severe dry mouth, dehydration, decreased appetite, nausea (sensation as if I’m about to gag, in my throat), and a feeling of fullness (and sometimes dull pain) in my abdomen. This is the only real thing that’s happened in the past month that’s “odd” – no nutritional, stress-level or other changes I can think of. I’m worried these symptoms might be indicative of nascent pancreatic cancer. It could be IBS, I suppose, but these symptoms arise irrespective of diet and stress, and they arose shortly after the CT.

Could these symptoms be attributed to the radiation and if so, what is the probability that that is the case?