Itchiness, Needle Pain All Over Body.

I used to be a very active person doing everything from sports to going all over the place. However, for the past few months I have only been sitting during most of the days. I think this is the cause of my needle pain . Currently, when it gets hot, I get embarassed or nervous, or I play a sport, a random needle pain occurs all over my body. It is not only an itchiness but a needle pain. I really want to get back to being active but this pain stops me everytime.