I've been in a similar boat, and I wish you well.
Seeing a headache specialist for migraine is key, as well as finding a benign way (benign to you, not worse for side effects) to prevent attacks. What has helped me all falls pretty much into lifestyle - food, removal of things toxic to me, sleep, my Goldilocks environment, heavy stress reduction, withdrawal from toxic people and topics, and navigating any hormones, including serotonin/melatonin - rather than any Rx drug-based prevention. If you have no tests such as MRI, EEG, or bloodwork, that is a decent start to determine a baseline and possibly find dormant viruses. I see you got most of this done.
For migraine attacks that I cannot prevent, I use triptan/ondansetron. I went from attacks every 3 days to 6 per year, and thanks to the prodrome (ability to smell much smaller amounts of substances, etc., and yes, I feel bad for dogs), I can take one pill each and never get those nasty headaches anymore.
Please don't assume a neurologist will understand autism for what it is, nor stay at least neutral and admit to not knowing when they are clueless. I have seen double-boarded neurologists/psychiatrists who could not for the life of them see that I was clearly autistic, and they ended up damaging me further and wasting precious time during which I could have tended to my well-being in other ways. If you do disclose, many typical physicians will start subconsciously mistreating you, regardless of what you said and what they thought and tested before your disclosure.
Overall, I feel my well-being is based on my trial and error. Having a doctorate and other advanced degrees and being accurate and specific in my language has helped me to assemble physicians who trust my self-knowledge, respect my conclusions, even learn (!), and take on a supportive consulting role, so long as it is within their professional ethics and oath. I had my worst-ever burnout around the time of diagnosis and lost a lot of NT life features at that time. It took me over a year to admit to myself that I CANNOT live a masked, pseudo-neurotypical life anymore unless I am okay with burning out again, possibly for longer and worse, and losing what high-level skills I have. That is, trying to get rid of pain and symptoms but abusing your neurology in other ways by way of physicians who don't know enough not to be harmful will likely not work.
Lastly, I noticed you use the term "oversensitivities". Hm. There is no such thing. You are more sensitive than allistics, and hyposensitive autistics. You would not call a healthy dog oversensitive regarding their ability to smell stuff. Or a raccoon that does a lot through touch. You are normal for who you are.
