When symptoms persist for so long, the best bet is to go to a Comprehensive Cancer Center. Although this may be inconvenient, it seems that where you live, you will not be able to get a diagnosis. To paraphrase what Gary said, "just because someone is an ENT or a dentist, doesn't mean they are capable to diagnose you.

Any tests, scans etc. that you have done, must be read by a well trained person. If the diagnosis is cancer, then you are best treated with a team approach.

This has been going on way too long for you to not take a proactive approach and get to the right place.

Good luck.