In the USA he say, "I need to talk you down from the ledge." I hope I can do that a bit.
It is very normal what you are experiencing. The stress and the nerves can really do a bad job on your head. I'd bet with 100% certainty that you do not have another cancer.
I am wondering if you are suffering from a bad case of acid reflux? Have you had that in the past? That is what your symptoms sound like to me.
Try some medication for reflux. See if it helps with the throat.
Cheers, and hang in there!