Possibly the wrong pilot bearing? Wiggle giggle and foot pushing usually gets the job done..... Maybe double check b4 wasting more time and effort?
Another thought would be splines on the input shaft buggered up, not sliding through clutch disc?
Or wrong clutch or installed wrong?
Put trans in gear and turn output shaft as you push?
Something just dont sound right.....

What did you change? Clutch? Transmission? Flywheel? Pilot bearing? Throw out bearing?