Hi, for starters:
- is the reaction immediate? (possible oral allergy, as opposed to something with stomach)
- get a blood pressure monitor and see if your BP is going low (dizziness and brain fog)
- does pulse get fast during dizziness, to compensate for low BP
"For some reason if I drink pop nothing really happens. I don't know if it is caffeine or what"
That's a big clue, so do more experiments. Caffeine without fizz, like coffee or just get all the fizz out of the soda before drinking. Sparkling water (fizz without caffeine) and/or non-caffeine soda. A large glass of lukewarm distilled water, if maybe it's stomach pressure and not what food you consumed.
Since cola is acidic, try orange juice, or vinegar and water.