I have a 98 durango and when i went to use it today and it wont stop accelerating!!!?

when i turn it on it revs like if i was steping on the gas pedal full speed but im not doing anything just starting it i noticed it when i was on the freeway luckily no trafic but still scary stuff, i looked to see if the overdrive was on but it aint, when i was able to stop it was only cuz i turned it off and cruised to a safe stop, i looked under the pedal and felt as if the cable was loose so what can it be and how can i fix it. ty for your time