Welcome Jon. You are right to be concerned about your health. You do have suspicious symptoms that needs to be looked into, not just with a CBC, complete blood count, but it can be something other than cancer too, and probably hindered of different causes with the same symptoms.

I would at least ask for a FNAB, fine needle aspiration biopsy, of the enlarged lymph node, which can be done by an ENT, I never did with my six FNAB, that were done by an experienced pathologist, who can even see by the sample slide right then if it's cancer, but is always sent out, or in house, for further pathology, confirmation. It's basically painless, takes 10 minutes in the office or hospital, and pretty accurate, high 90% range, and a biopsy is the only thing to prove cancer. A CT or PET scan in addition. A scope, which is done on your visit, may have other findings, and can dictate a different plan of action than what I mentioned. Some may want to do a a triple scope, under anesthesia, with biopsy, other surgery, work-ups to rule out cancer, but it's not cancer until proven by biopsy, but still is investigated as cancer suspicion, until proven otherwise too

Sometimes there are no symptoms with some type H&N cancer until its advanced or very advanced.

Good luck.