You need quick and thorough treatment. Because it is non HPV the node should be removed unless it is very small, and you should then have rads asap - they may forgo the neck dissection in preference to having you start radiation. My one concern with that is if the radiation doesn't kill it you are in for another surgery, and if it persists then you may not be able to have more rads this close to finishing your other treatment. Having surgery, while NOT fun, was some comfort to me as I knew that most or all of the cancer was gone post op, then rads and chemo (hopefully) swept up the rest assuming there still was some present.
With an occult primary - you said you were biopsied on your left lateral tongue, but got inflamed tissue. I would wonder if perhaps they didn't go deep enough. My first biopsy was similar to yours and sure enough the tumor was actually either deeper than the area removed, or the guy didn't remove the correct tissue. If you've had a scan and there's nothing then that's great go with rads and push push push for soon.

best of luck.