I don't have much experience in this area. I broke a clutch cable in a 60's car once and I could still shift it and managed to get home. When I had to stop I made sure to slip it in neutral on a hill. So it sounds like the transmission is OK. I had a slave cylinder full of air and the pedal would go to the floor and didn't want to return. You don't have air in the system. I've had a throw out bearing go bad and it sings and howls, so it's not the throw out bearing. Worn out clutches slip like crazy, a broken spring on the pressure plate causes a real rough engagement when letting out the clutch. (I'm going back to my youth experiences)

I've never had a pedal that couldn't be pushed down. Something failed completely in the area your looking at. If it was me I'd pull the transmission and look at the throwout bearing arm and pressure plate. It should be obvious since it is a total failure in some part. Don't buy parts until you know what you need if possible.

Les