Could be plenty of things, master cylinder or slave cylinder, air in the system, contaminated brake fluid (the clutch shares the brake fluid reservoir), clutch release bearing failed, pressure plate worn out or broken, dual mass flywheel issues, gear selector cables out of alignment or stretched just to name a few.

Really needs to have a mechanic look at it. You say there was a leak somewhere, get that rectified first, get the clutch re-bled and the selector cables checked. Then go from there.