Check the shutoff under the sink. If it is 15 yrs. Old or more than maybe the rubber stop/washer has become disengaged and has clogged the faucet line. Turn off the stop, disconnect the supply line, using a flexible supply line connected to the stop, turn the stop back on with the supply line emptying into a bucket. Have someone standing by in case the stop won't shutoff and you need to shut the main water down, either at the water heater or the main. If water comes out with force than your problem is at the faucet, if there is not much water than you may need to replace the stop.