First things first : THERE'S NO NEED TO SHOUT. Caps lock can be turned off quite easily.

The fluid level will not cause the clutch to slip, nor will the condition. If its low or poor quality, it will usually make selecting gear difficult as the clutch will not disengage correctly. What you have is a worn clutch friction plate or weakened pressure plate.

Either way you'll need the gearbox out of it to replace it and whilst in there, inspect the flywheel and replace that too if it has heat damage from the slipping.

Ah, I forgot to add the possibility of oil contamination, it was late, I was tired. Good call bathtub tom.