Mine was close to T1N1 but after almost 23 years it has not reoccurred. I have had more issues relating to the radiation treatments than anything else. However, it is certainly understandable to be concerned / worried about reoccurrence. Everyone who has gone through this nightmare likely thinks about reoccurrence of the cancer, particularly in the first year where as I understand it if the cancer comes back it is more than 70% likely in the first year after treatments. Second year takes the next 20% roughly.
Eat healthy if you can. Stay healthy. Avoid crowds and health risky behaviour. The success rate for cure of this cancer you had is rather high compared to other more common cancers. Try not to dwell on "what if?". Live well with your second chance at life. But if something doesn't feel right or is getting worse as the weeks go by, then certainly get to your doctor or oncologist to have a look-see. Courage.