We recently published an article(on this site) on a 10 year study using a “refractory rating scale”; one of the conclusions of the article was that all groups, mild/mod./severe, improved over time. I believe it is important to find a doctor/program that you feel comfortable with, and keep plugging away with different medicine regimes, even if they are not immediately all that successful. If you have “refractory” headaches, which means “difficult to treat, the usual things do not work all that well”, keep trying. We also keep on trying with non-medication therapies(exercise/diet/acupuncture/chiropractic..whatever works…).
If you research different strategies, and suggest them to your doctor, that may help. An informed person, with research in hand, often does better in our health systems.