low pressure after hot water heater replacement

our hot water heater leaked and ruined our floors about 2 months ago. it was replaced and all was well except the kitchen sink (which is about 8 feet away from the hot water heater unit) now has extremely low water pressure. i would say it lost about 70% of its water pressure immediately following the hot water heater breaking. also next to the kitchen sink is the dishwasher, which has been increasingly showing bits of soap in the glasses after its cycles. that leads me to believe the dishwasher also is not getting enough water pressure. the sink does not have hot and cold valves, just one valve that you rotate to choose your water temperature.

all the other faucets/tubs in the house get exactly the same amount of water pressure as before the hot water heater broke. the kitchen pressure is so bad it is almost unusable for most things except washing your hands.

also sort of related but not really, the kitchen sink has always had really funny tasting water. it doesn't taste funny out of any other faucet, but it tastes so strange coming from the sink that we have to use a brita filter for the water. there are also small particles coming out of the water we don't see in the other faucets. i wonder if the combination of those two things means something is wrong with the actual faucet and/or pipes.

anyone have any suggestions or places to look/check? thanks.