Help Witha running/jogging problem?

My friends say i'm wimpy 'cause i'm not a fast runner and when i run my tendon starts hurting really bad. Am i? Also when i run in PE how do i stop my Achilles tendon and my and knees from hurting? how do i learn to run really fast? The amount of time needed does not matter. What should i think about to take my mind off of actually running and being tired? Thanx to everyone that answers!