A month ago, I hit my head against the top of my car (it appeared an innocuous accident at the time) and I've had strong headaches every since.

My neurologist told me that my headache is "post traumatic" and that it's a tension headache. He prescribed me 20mg of Nortriptyline, which

I've taken this medicine for 2 weeks now but my headaches haven't got better and I'm quite concerned.

I'd like to know:
(a) whether I'm taking an appropriate amount of Nortriptyline, as I've read that some people take up to 75mg of it a day, and
(b) whether my headache can be treated in any other way, whether through western medicine or otherwise

None of the painkillers I've tried have relieved my pain.

I would be very grateful if you could help me with this.