sumthing hurts in my stomach

hi my name is kelly am 18 years old.......i relly need your help  evry day am feeling sick sumthing hurts in my stomach but i relly dont no wat it is then a get a bad head my back hurts i relly don no wat it is please can u help and tell me ??????????? and yea one more think then a eat then a feel ok then later about 2 or 3 mins it starts again