I completely understand your pain about grocery stores! As much as they trigger me, it's one of my few times during the week to "get out of the house" without seeing a dr. or physical therapy, vestibular therapy, etc.

For me, the whole environment of the grocery store is overwhelming. So I've found some ways to "tone down" the environment.

1) I always wear ear plugs. They filter out most of the background noise, (especially the squeaking and grinding of the cart wheels), while still allowing me to have a conversation with my boyfriend as we shop, or with various workers at the store. The ones I have are sportsmen's ear plugs that fit inside the ear, (not the big bulky headphone looking ones).

2) I wear my sunglasses, at all times. And yes, people look at me oddly, but it really turns down the flourescent light overload. Knowing that I can go to the store and go home relatively unscathed, is worth all the weird looks!