My sister has had a drug resistant headache and neck pain for 14 days. All tests are normal. What's wrong?

25 yr old healthy white female. Has not traveled out of US but spent time in woods in NW US a year ago. Presents with left sided headache, neck pain, and low grade fever for 14 days. LP was done: CSF looks clear and cultures come back negative. MRI and CT are negative for swelling, bleeding, and excess fluid. No signs of trauma. No history of fall. Pain gets worse upon standing. She complains of light and noise sensitivity, dizziness, blurred vision, and both dull and stabbing pain in her head that doesnt respond to oxycodone, morphine, dilaudid, or other pain medications. Has had migraines in the past but says this one feels completely different. None of the doctors at the hospital have helped. Anyone experienced this before or have any ideas?