Im experiencing extreme itching and pain on my stomach and legs when i run and when its cold out its even worse. i get welts. its like a stinging sensation and its so hard not to itch!

Urticaria: This sounds like cold induced urticaria. Exposure to cold and vibration can be cause of hives. Try Claritin prior to running in cooler weather.

? Physical urticaria: Agree with Dr Annisian, could be a sort of physical urticaria, I.e. induced by physical agents as extremes of temperature, vibration, etc. Better see an allergist or a dermatologist , good luck