I was diagnosed with occipital neuralgia in college and suffered debilitating migraines as well… the kind where I could barely lift my head up off the pillow. I was able to trace the pain in my neck/base of my head back to TMJ since I broke my jaw from a softball to the face at age 3. I went to a chiro/PT who did dry needle therapy (like acupuncture but needles go in much deeper) to break up all the old scar tissue. It left me extremely sore but wasn’t painful, he would do all along my jawline on my face and neck/shoulder related muscles 2x/week for almost 3 mo then gave me PT exercises for TMJ. Happy to report its been over 12 years without a migraine and the pain in my neck is nonexistent. As far as sinus problems with the change in weather/pressure, I have those as well - mostly from bad allergies/tonsil removal bc they used to catch everything and I would get nasty infections. The only thing that works for me is daily nasal washing 2-3x/day using Xlear nose spray (contains xylitol, grapefruit seed extract, saline). The xylitol forms a film to trap bacteria, it’s kept my son from having any ear infections while in daycare the last 2 years as well. You should look into both of these things for your ailments, hope this helps! Also - I played competitive volleyball in HS/college and also had the fainting issues which I thought was due to low blood sugar, but realized it’s bc I have low blood pressure so actually more neurological vs diet-related. Mine ended up being linked to anxiety, meditation has helped but also grew out of it in my 20s. The only thing that makes me dizzy or have a headache now is a bad sinus infection so started treating that and immensely better.