Newbie: 4 years of these strange symptoms. Please help!

Hi, I know this is rather lengthy, but any help/advice on this issue from you guys would be amazing: I'm an otherwise healthy 25 year old male but for the past 4 years, I've been experiencing something in my head that has nearly torn my life apart—and the killer is: I still don't know what kind of headache it is. I have always been tempted to avoid even describing it as a headache (I’ve had cluster headaches that resemble a hammer hitting my head, and this is not that). Instead, it is an extremely dull, lingering, uncomfortable, slight pain/feeling in my head (mostly forehead), but unlike the description of a “tension” headache, the worst part is that it makes me extremely nauseous and/or irritable.

The main culprit: exercising, whether it be just light cardio or heavy lifting. However, unlike an "exertion" headache, I never have an actual headache during my workout. The “headache” always arrives about 30 minutes to 2-3 hours afterwards, almost in sync with my blood pressure coming down. Before that workout, I feel like a million bucks. During the workout, still great (sometimes slightly lightheaded but I think this is just because I have poor blood flow to my head – I frequently feel this when I stand up to fast). After my workout, the headache feeling, nausea, and irritability begin to kick in - even if I make sure I eat plenty before and after.

Aside from exercising, the times I experience this headache is after I have a high-stress, high pressure situation such as giving an extremely nerve-wrecking presentation. The main agitators once this headache begins: Looking at any type of screen, trying to concentrate on work in the least bit, or being hungry. Obviously, I still have to go about my work days. So, most often, I try to fight through this head feeling/nauseousness. That’s when the irritability usually kicks in. It becomes so strong that even the slightest thing (mistyping a word) will make me want to smash my computer in half and punch a hole through a wall. It causes me to tense up - I catch myself unconsciously holding my breath in and then I have to take a deep breath and close my eyes for a few seconds. But before anger disorder pops into your head, I have absolutely zero frustration/stress when I don’t work out for a few days and other than that, I'm an extremely low-stress person.

As mentioned before, being hungry makes the headache/nauseousness about 10 times worse. Eating some food doesn’t necessarily get rid of it, but it makes it better. The only cure once this headache begins: Laying down/closing my eyes, not looking at screens, and not concentrating too hard on anything. Strange, possibly related symptom: Another strange thing that happens is that sometimes the night after I work out, I will wake up about 2-4 hours after falling asleep drenched in sweat, out of breath, lightheaded, and having kaleidoscope vision. I can usually get back to sleep after several minutes but the cycle repeats and I have a miserable next day. I've been to several doctors, had dozens of blood tests, been to two different neurologists, and had two MRIs, all for them to say that I am healthy and I am just suffering from "general" migraines and that migraines are such a mystery in the medical world that you can only keep trying medicine until you find one that works. I’ve been on tons of Advil, naproxen, Excedrin, CoQ10, and many other “migraine helpers”, all of which have not helped whatsoever. I haven’t had caffeine in years, and have followed pretty much every dietary plan for migraines possible. My sleeping habits are the exact same every day. I don’t know what else I can do. And I know that “not exercising” is the obvious answer from what I described above. But 1.) It’s not all exercising as I mentioned before and 2.)

I want to be healthy. I feel like the main activity for keeping a person healthy is absolutely tearing me apart. Any help or advice from you guys would be amazing. I just feel like there is nobody who understands, not even doctors, and finding this site is a sign of hope for me. Thank you!!! Jackson