A friend of mine suffered vertigo and with her it was a purely mechanical problem. You might want to explore
It's possible that what you believe are triggers are purely coincidence rather than a nutritional problem.
Youtube has a LOT of videos on how to do the exercises:
And here's an explanation of the disorder. Sounds like you might want to find a doc that is familiar with this condition, perhaps it's something chiropractors are familiar with? At any rate, I would not just start doing the exercises willy-nilly. Seems that there is a definite pattern and also some that you may need assistance with:
Vertigo is a disorder of the middle ear, caused by small crystals that have colonized in a sensitive part of the inner ear. These crystals become displaced, causing the dizziness of vertigo. Usually a physician who specializes in dizziness and balance disorders will perform The Epley or Semont maneuver. These maneuvers will settle the displaced crystals. The Semont maneuver is a calculated and rapidly moving exercise, performed only by the doctor, in the safety in the doctorís office. Similar to the Epley maneuver, Brandt-Daroff exercises can be done at home. These exercises are beneficial for anyone with dizziness, vertigo, imbalance, lightheadedness, or faintness. They are safe and easy to perform.