Bad headaches for several weeks (antibiotics haven't worked) and lump behind ear, near hairline (firm but moves) on blood test white blood high?

Infection: You likely have an infection with an enlarged reactive lymph node behind your ear. This needs to be further evaluated, perhaps even biopsied to make sure this isn't some kind of tumor. If it is infectious the headaches might indicate chronic meningitis (not likely, but scary if true) so don't delay getting checked out.

Different antibiotic: You may need a different antibiotic because fever, high white cell count, and severe persistent headache suggest an infection. You should see someone as soon as possible because the infection can potentially spread to the brain.