1995 Jeep Cherokee clutch

Engine Mechanical problem
1995 Jeep Cherokee Four Wheel Drive Manual 140000 miles

hi when I first get in and drive the jeep the clutch is normal, but after about 15 minits it starts geting harder to get it in gear, reverse is very hard with a lot of crunching, then ill get in it next morning all is ok again, then after 15 minits starts again can you tell me whats up please