I"d imagine the transmission inputshaft that the throwout bearing slides on is rusty or crudded up and is not letting the clutch springs and push it back when the pedal is released.
If it were me, I"d remove the cover plate at the bottom and see if i could spray some WD-40 or brake cleaner, etc up on the shaft to get it to release. There may be a a way to pry it back. T
The other possibility is that the return spring on the pedal broke or the bushings in the case are crudded up so Spray some WD-40 on those.