i got a new clutch put in about 3 months ago and lately if i go on a drive on the highway at around 75-80 mph for longer than 30 mins when i get off the highway my clutch pedal gets real soft and it seems like my clutch goes out and the car will shut off but then after like 5-10 mins it goes back to normal any ideas?

its the same as burning or riding out a clutch. The clutch heats up over time trying to hold friction between the tranny and motor. Either dont drive so fast so long, or get a stronger clutch. This is why drag cars use 6 puck discs instead of a normal one. A 6 puck when heated up doesn't lose gripping power, or start to tear up into hair like fibers like urs is doing when it becomes weak. Id get a better disc or whole clutch kit once yours goes out. Either that or your slave cylinder needs replacing/ clutch hydrualic system needs to be bled.