Your story really touched me. Specifically your hysterectomy due to endometriosis, hormone issues, migraines, smoking (I am also a smoker, have been a non-smoker too). You sound desperate and I know that feeling too.
I have suffered horrible migraines for 42 years, the past year has been the worst, getting up to 4 migraines per week. But, I am getting better. What I have come to realize is that doctors do not have all the answers we would like them to. It is trial and error for them in many cases. I am lucky to have 2 very good (and kind) neurologists.
I had a complete hysterectomy at age 35 and had many problems with HRT. It took a long time to find the right brand, dose, etc. I felt awful for the first year after the surgery. I have been off HRT for the last 3 years, stopped taking as new doctor advised me I had been on it too long. No problem tapering off it.
I have found my body to be VERY sensitive to everything - medicine, weather, stress, etc. I think perhaps your migraines began as a reaction to everything going on with your health? You are on a lot of meds, I have been too over the years. I think if you have a sensitive system, then each new drug has the possibility of wreaking all kind of chaos, side effects, etc.
Sounds like you are doing a lot of the right things! Exercising, eating healthy. Hang in there.....it will get better.