I also have constant headaches closing in on 430 days in a row now. Last week I finally went to a headache clinic along with my concussion professionals. Later this month I see a neck specialists. As far as meds go they tried the following for me.

I do take Topamax at bed time though and that dosage is being increased...I have no side effects from it. Do you take yours at night? That might be the key to not feeling groggy from it.

Amantadine helped at a lower dose then it was raised and caused numbness in my face. I was taken off of it then.

Elavil was given to me in the past with no help but caused restless legs.

Vivactil seemed to help a little and did not make me tired, but gave me dry mouth.

They have tried a couple blood pressure meds, but my blood pressure is low normally so I was taken off them as a safety precaution.

The headache clinic gave me Imatrex that I can self inject...suprisingly painless and it helped for a bit. At this point any relief is welcome! The
trade off though is he said no OTC pain relievers ever I am not sure I can live up to that. But the doctor did seem to be familiar with not just migraine suffers but PCS patients with persistant headaches too. Gave me a little hope. You have to remember things work differently for each person. Maybe there is a headache clinic near you, or contact the doctors you were working with and dicuss it with them. Best of luck to you and feel better soon!