I have a reoccurring headache on my right side. it's behind the ear. i can point to exact spot and painful to push ?

??Mastoid infection: That is the location of your mastoid sinues. Used to be a common infection but much less common since the advent of effective antibiotic treatment for sinusitis!! I cannot recommend treatment on this platform but suggest you mention this possibility to your Primary Care Provider

? muscle tension: The most common is a muscle tension headache, but it could also be coming from arthritic-type changes in your neck: a cervicogenic headache. Migraine could also be a consideration, although migraines more commonly occur around the eyes. You should have this evaluated: testing including CT/MRI testing should be considered to exclude tumor, which would be unlikely. Best wishes.