I've started experiencing night sweats, even when it's not hot and i'm not feeling. there's also excessive sweating when i am stressed or anxious. i sometimes wake up with a dull headache and my head feels heavy. i am constantly tired. should i worry?

Night sweats: True night sweats occur because of fever that breaks during the night. Get a thermometer and take your temperature (and write down the results) 3-4 times a day for a few days. See a doctor soon if any fever (some temps >100F or 38C). If symptoms continue with no fever, probably not a serious health problem -- but see your doctor for sure if your symptoms continue. Good luck.