I used to have low blood pressure. One doctor told me that it was generally healthier than high blood pressure, except that mine was so low I could have a bad accident fainting.

So I started eating saltines. Surprisingly, the salt helped.

I've never had the visual experience you have, though.

On the other hand, sometimes I have dreams that are related to my health, and sometimes they are a bit symbolic. I wonder if your visual experience, with the grid, could possibly be a "dream" related to your blood pressure?

One other thing... I used to feel like I was going to faint a lot, though I seldom actually did. I'd be dizzy a lot, but not faint.

Then I had B12 replacement and I stopped having that dizzy feeling so much of the time, and I didn't feel as if I was going to faint whenever I got up suddenly.

You might try some B12 and see if it makes a difference. If you do try it, though, get the Methylcobalamin kind. It works MUCH better.

I hope everything sorts out for you.