Very well written story. I’ve suffered with migraines since I was a small child. Like you I didn’t receive a diagnosis until I was much older. Successfully managing and coping with the illness means that it becomes a big part of your identity. Unfortunately it does dictate what you can and cannot do with your life. Sometimes trivial things like not being able to go to an outdoor concert because of cigarette smoke and sometimes significant things like not being able to be an astronaut.
Maybe the new treatment won’t open your previously closed doors but will instead open new doors to opportunities for which you haven’t dared hope. You sound like a survivor. I suspect you will adapt and thrive in a new migraine free world.