Clutch problems..nitrous

Ive run about 3 bottles and 2 trips to moroso west palm with a
65 shot and my clutch feels like its going. When i hold the pedal down for to long it stays on the floor. i lift the pedal back up by hand and it gets pressure again. it is getting harder and harder to put the car in gear. i have to pull it pretty hard to shift gears.
is it the master cylinder or the clutch? the clutch pedal is also very hard for a hydro clutch and when i press the pedal down 1 inch the clutch ingages how do i fix my clutch and tranny?by the way it killed my track times off the line. my best run was a 14.4 where its usually a 13.xx i beat a supra TT top end and l lost the race by .1 along with a mustang GT. when i let out the clutch the engine bogs down.plz help!!