Really weird pains...?

Something really weird happened to me just now and im not sure if I should be concerned or not. I suddenly started sweating like a pig, I felt like pins were going in me all over my body and it was so itchy i had to take everything off except my boxers just to scratch. My left side of my stomach is hurting really bad its a sharp pain and hurts more when i push on it. Im also having really bad pains on the lower left and right side of my back The wrost part was the heart pain where i felt like i was getting stabbed in the heart. Also lately ive been having really bad sharp pains just beneath my rib cage on the right side. Im sorry if I sound stupid but im only 15 and im kinda worried. I recently had an appendectomy about 6 weeks ago. Is this still part of recovery? Or something else?