I bet your problem is:
First, Over-stimulation. This sets off a mini-anxiety issue.
Second, You pay attention to this little struggle it and it magnifies.

The triggers are
Visual stimulation.
Bold patterns on the carpet
Signs and other visual stimulation in stores, A shelf with hundreds
of products ate eye level
When driving, objects moving around you

Sound stimulation
Too many voices talking too you. (your talking is only a problem if
others talk over you, in most cases)
Ambient sounds that are common is stores
Echos, a problem in larger buildings, malls etc.
The PCS brain hear echos that the non-PCS brain easily ignores

The brain naturally wants to make sense of our surroundings and stimulation. But, it usually can filter out the vast majority of sensory stimulation. The PCS brain does not do this well so all of the sensory stimulation is processed, or at least the brain tries to process all of it, and CRASH, the brain overloads and systems start failing.

For people with Type A personalities or higher levels of observation skills or intelligence, this is more of a problem. As you said, you process in a linear fashion.

But, PCS makes it so the brain does a lousy job of sorting and organizing so it gets hit with this abstract pile of chaos.

We can choose to ignore it. It is a challenge but the simple explanation is that we need to learn to pick our battles. The pattern on the carpet is not a worthwhile battle. Try to avoid looking at it. The sounds around us can be reduced with ear plugs. Mack's makes good ones. Carry them everywhere you go.

Socializing needs to be moderated by not getting involved in group discussions unless everyone can learn to not talk over each other. Even then, sounds coming from the sides can be a struggle. It is easiest when you can look directly at the person who is talking.

In a restaurant, try to sit near a wall or corner (best). This limits the angles the sounds are coming from. I have to do this or wear ear plugs. Sometimes both in a noisy restaurant.

Driving is a challenge. I do best without the radio on. No or minimal talking. Avoid busy times if you can.

And, try to let go. Pick your battles. PCS makes the world too abstract so we have to make an effort to ignore much of the chaos.

It is a challenge that we can win once we know the system.

btw, Your dizziness does not sound like a vestibular issue, nor a movement induced issue. The Epley is for movement induced dizziness.
I have movement induced struggles. I can only make major movements on one plane at a time. Lean forward in my chair, pause for a second, then stand up. I can't do them both in the same movement.

Hope this helps.

My best to you.