Leo,
I second what Christine said. You're making yourself crazy with this. There's nothing I can add or say that will alleviate your concern. I'm not a doctor and cannot derive even a good guess on what's going on with you. However, based on what you've posted and what your ENT has said, it doesn't sound like cancer.
Perhaps there's someone you can speak with?...a counselor maybe? You need to relax and get off the worry-go-round. I could look up the symptoms of several diseases and find I'm suffering from at least one or two of the symptoms at any given time. The mind is a funny thing. Too much worry and stress could have you feeling things that aren't there.
It really appears your ENT feels you're Ok. Hopefully the CT will put this to rest for you and you can go on about your life.
Positive thoughts and prayers
"T"