In the middle of driving, I couldn't shift my 6 speed and had to pull into a gas station to park. Once turned off, I could put feels the gears, but once turned on, I couldn't and the clutch pedal itself is very difficult to press down. What guesses are there that either the gearbox if busted, the clutch needs replaced or a new tranny is needed... or it's low on clutch fluid?

THANK!!!!!
Crossfire Limited, Sapphire Silver, 58K miles. This is the first big problem I've had with it.