Hi,
Apparently, you must be getting dehydrated if several glasses of water returns you to normal. I'm 79 and I've noticed that as I am older, I require more water now than I used to. Just drink a lot of water. Take a bottle or two of water with you when you go places like to a doctor's appointment where you may have to wait a while. Water helps all aspects of your body.

I have no idea what the electrical buzz is but it might be a side effect of dehydration since it goes away when you drink water.
I wish you the best.
PML