Hi Chuck,
I'm not trying to frighten you but there are a number of us here who had no lymph node involvement. I had none yet my cancer was staged at III/IV, so your oral surgeon is flat wrong about it. That's why I always recommend seeing an ENT or head & neck surgeon (preferably one from a comprehensive cancer center).
There's only one way to get a definitive answer - biopsy and pathology report - xrays and scans are subject to interpretation.

If it is an infection it should be accompanied by some pain. If it responds to the antibiotics then you're home free - if not, get a referral to a competent ENT and find out for sure. And yes, there are benign conditions that it could be also.

In all fairness to your doctors, oral cancer in 20 year olds is fairly uncommon and that's why they don't believe that's what you have. My head & neck surgeon told me that the 6cm x 3cm tumor growing on my tonsil might be benign also (until the biopsy report came back). Since I haven't drank or smoked in many years I didn't fit the profile either.

It is good that you are taking this seriously. If, in the rare possibility, it is cancer, the earlier you have treatment, the better the outcome will be. In any case - ditch the dip. We would hate to see you back here in 20 years saying we told you so...