My kitchen sink has recently become difficult to shut off (we have a pull-down spray nozzle with single handle control). It feels like we are fighting to shut the water off against a high water flow, but the water pressure coming from the faucet doesn't seem abnormal. The other night, the hot water started leaking under the sink, so my husband shut the hot water nozzle that's under there. That seemed to solve the shut off issue and we noticed significant less pressure/difficulty when turning it off and on. Last night, we noticed the pressure was back, and it's difficult to shut the water off again. Obviously, we need to fix the hot water leak, but is there any common issue that would cause this pressure/difficulty in shutting it off, and (if so) is it something a layman could fix?