Kathy -
Don't waste too much time and energy in thinking about what you think may have helped. Even with aggressive treatment in conjunction with the removal of one lymph node, (radiation / and or chemo), recurrence of SCC H&NC is possible. Conserve your energy and focus on becoming cancer free.
Also I think the cause of the cancer is somewhat irrelevant, at least on this forum. Like you, I was a social drinker, non-smoker, non-
HPV, athletic and active when first diagnosed. We fall into the 5 to 7% of patients that have no defined link or listed as genetic causation.
HNC is a viscous little cancer and will take a lot of effort on your part to get through the treatments. your oncology team should be able to help you with any issues that you encounter along the way. Trust them, but ready to question them as well.
Good Luck