1999 RM125 barely moves in first gear?

My bike ran perfectly fine for the longest time and still does. I took it out of the garage today and started it after i cleaned the spark plug. I put it in first gear and let the clutch out slowly as usual. It was almost like riding an automatic bike after that. It seemed the clutch only partially disengaged or something. I gave it some gas and it hardly moved. Please help i am supposed to sell it tomorrow.