Might be worn out or might be something simple (if you're lucky).
#1 - pull the floor pan up on the "driver's side" and make sure the valve-arm that is hooked to the clutch pedal is returning all the way. Often when the return spring gets oil and/or there's debris in there- is it blocked from returning all the way.
#2 - try opening up the "rate of shift" adjustable jet with a screwdriver. That can sometimes make a huge difference.