Tragic comic, RICHARD PRYOR, is in so much pain that he's begging nurses to let him die naturally of multiple sclerosis.

The STIR CRAZY star is battling the devastating disease, which leaves him needing round-the-clock care. A source says, "On one really bad morning recently, he screwed up his face and muttered, 'Just let me die. Why don't you. I just wanna go. I ain't no good here.'"

JENNIFER, the fourth of Pryor's five wives oversees all of his medical care - even though their marriage ended in the early '80s. She says, "Richard gets deeply depressed and often doesn't want to get on with his life. He'll turn stubborn and refuse to do his exercises or drink water. And without water, an MS patient can't breathe. "Richard's black moods are too dangerous to let fester. If he loses hope, he can't battle his disease."

However, the legendary funnyman still occasionally shows a flicker of his former self. Jennifer adds, "One time, he was sitting there staring at his caretakers preparing his food, looking as helpless as can be. But when they asked him what he was thinking, he replied, 'How much I'm paying you m*****f****r!' "And one day, when Richard was particularly down, his nurse CORINA told him he's too important to let himself go. He replied weakly, but wryly, 'And don't you forget it!'" (ALS/NE/RGS)

Source: WENN