I have a pain in and behind my right ear, almost feel like when it is bruised. and my body aches, especially lower back. what could be the cause?

Infection : You may have an infection. If the symptoms persist see a doctor and get a definitive diagnosis

Infection: You may have an infection. You need to consult with a family practice physician or an internal medical doctor.

Ear: Pain behind ear could be associated with otitis medis or mastoid infevtion, external otitis, occipital neuritis, adenopathy of posterior chain

If the pain is bad..: You need a medical examination if your pain is bad enough to disturb your normal function. The ear pain probably has no connection to the back pain. It is hard to tell the cause without medical check up and checking your CBC(complete blood count). I would advise you visit your Primary care physician.