I can do without most people with or without cancer most my life lol. Is this feeling different than pre treatment? Some feel a loss after treatment, get depressed, as Christine mentioned, for a number if reasons, one is all of a sudden your support team, dr visits, tests, and routine suddenly ceases, and feel something is missing. Head and neck cancer also has a high rate of depression compared to other cancers. Maybe join a support group, see a counselor, have your blood levels checked for any deficiency, TSH, Vit D, Testosterone, hemoglobin, A1C, glucose for diabetes, which can effect quality of life, mood, health.

Good luck.