Nah Fluid probably have nothing to do with it. The clutch disc is probably burnt out or the pilot bearing has gone bad. If you step on the clutch pedal and the pedal is shaking, either the pressure plate, clutch, or flywheel is warp. Put your e brake on and put it in 5 gear and slowly let go of the clutch pedal. If you dont stall than you need a new clutch. If it do stall, than that probably mean that the pilot bearing has gone bad causing the shaft in the tranny to have too much free play. But to acutally fix it, the tranny have to be remove and that gona cost a good amount of money unless u can do it urself