Shooting severe pain in the back of my ear bone and only other symptom is heart flutters. i had a pretty bad flu virus a few days ago and now this has started. should i be worried?

Antibiotics poss req: Behind ear is the mastoid sinus. Infection in this sinus can become serious (called mastoiditis) because so close to brain. Must be evaluated. If a nearby major Hospital, best choice: go to ER because CT scan may be required. Otherwise go to ENT doctor I recommend do so right away. A big Hosp will have a fast low radiation CT. I'm not 100% sure this is diagnosis, but you must get eval rt away.