Suggest Treatment For Muscle Cramps

i am nicky, i am 24 years old, i was studying, my hand was jitter, i can t lift any weight, if i do pull ups i can t do more then 2 but 5 years i was do 10 pull ups but now i can t . and also muscle cramps happen to me, mostly when my wrest move up and down slowly i can see my hand was jitter, and i can t play guitar before the crowds when i start playing instruments at the stage my hands are jitter. there is any solution for this please tell me