What Causes Pain And Numbness In Thumb And Pointer?

Since thursday I had a litlle tingling pain in my left thimb only. Today in Monday i am experiencing severe pain in my nerves of thumb and first finger. Severe pin pricks pain also a numbness feeling in the thumb and finger. Sensory feeling is less as compared to other hand. I had experienced pain in my nerves of whole left hand I tried to explain it to doctor but they couldnt understand it. It usually happend when I am extremly tensed or tired and havent slept properly.

Th pain in my thumb it happened the first time ever but leaving my whole left arms so heavy. the pain sometimes feel like traveling through my wrist but mostly the pain is in my thumb. In appearnce it looks normal but I feel like its swelled. Please help what is wrong with my hand?