I haven't found a place to post this and thought this would be the best place, because I do have head pressure, though not a headache.

This occurred on Monday, Memorial Day, just a few days ago.

I smelled the ammonia and heard bell ringing sounds afterwards. Two hours later I sitting at my computer with my computer glasses on suddenly my eyes and brain couldn't work together. Difficult to explain. I'm usually very good at spelling but suddenly I couldn't spell correctly. Then the palms of my hands got ice cold and began to sweat. I was sweating elsewhere but normal temperature. My heart rate became irregular but slow. I have a slow heart rate as it is. It sped up after that to 60, fast for me. Then it went back down to the 50s and I felt strange. I felt as if I'd keel over. I had photosensitivity, as in I didn't like looking at my computer screen, but no headache. I grabbed some aspirin and took 4 baby ones thinking this was something to do with my heart because of the irregular heart beat. I had some chest pain afterwards.

After a while, maybe two hours later, I had pressure in my occipital area of the skull (the back of the head). There was no headache. I had nausea at that time too.

Since then I've had more symptoms. Here's a list of the most bothersome:
Nearly constant nausea
Occipital head pressure, can't rest back of head on reclining chair without aching discomfort
Inability to look at television/computer without symptoms described above
Dizziness
Difficulty with balance, holding things when get up and balancing self with walls
Ear pain radiating into teeth
Shower water on head is painful, can hear water in head
Fleeting numbness left side of face from lips to head above ear
Ongoing not having the right words, switching words with words that don't mean the same thing, such as mow the carpet, vacuum the lawn, I actually said that
Emotions all over the place and inappropriate emotions
Zero sex drive

More history about me: Uncontrolled Hashimoto's Thyroiditis with thyrotoxicosis on Mother's Day which required hospitalization but usually hypothyroid, past Perimyocarditis with pericardial effusion and atrial fibrillation.

What I think? Something to do with my pituitary/hypothalamus. My doctor is mystified with my symptoms and with treating my Hashimoto's.

More info which I just figured out this morning:
I'm fine when I first wake up - if I took Tylenol before going to bed - but if I move my head or eyes all my symptoms return. First is occipital pressure/ache, then nausea, then eye pain. I can keep the symptoms somewhat controlled with Tylenol. And when these symptoms come on I smell this ammonia/burnt smell. The smell is intense.

Overall, my symptoms remind me of a severe concussion I had in 1983.

Ideas anyone?