Sharp Shooting pains in my stomach?

The past 2 days ive had stomach problems i dont know if its just gas or somethign wrong. however the symptoms i feel is when i lean back in a slouch my stomach feels tighter an has a sharp pain when i sit up or try to get up out of a chair my stomach has the same pain as if i cant bend over due to the pain. can someone tell me what this could possibly be? an earlier this morning i couldnt eat anything nothing settled on my stomach an i felt dizzy all day cuz of not being able to eat