id check for air in the line, that happened to me...my pedal just fell to the floor and i found otu that one of the lines were busted so it was slowly leaking fluid and letting in air.

you shouldnt hold your clutch down like that. your e-brake is there for a reason and it puts a lot of stress on the components such as the throwout bearing and that shit goes out, you are going to have to drop the transmission to change it.