I have low water pressure in my upsatirs kitchen but not my upstairs bathroom/Shower and toilet. They both are on separate water line sleading from the outside to the outside on two different meters. When both are turned on the water pressure in the upstairs kitchen slows to A Trickle. What could be the possible problem. The water into the bathroom is running fast and when turned fully on seem to have a lot of air behide the water flow.

I know it appears to be water pressure but it is actually a volume problem. There is a partial clog in your upstairs faucet. likely the aerator or the mixing valve. First try removing the aerator and tell us what happens