Could be you have an infection that has settled into the lymph nodes in your cheek, like an abscess
from a tooth or infection in
your ear. Feel of the lymphs in
your cheek, and also in the neck between the throat and the corner of the jaw... if either area is tender to the touch, that's an indicator you have an infection in your head somewhere. A dentist can determine if it's a tooth. Your regular doc can do some bloodwork to look for infection, bacteria, and so on.