Serious Problem

Ok a couple of weeks ago it froze here in dallas tx. After it did the next day i tried to start my car but when i did the accessory belt pop off. I was ok ill just put it back on, thats when i ran into the problem, My tensioner only goes down and the belt if suppose to go under it.....WTF. I already tried everything and everyone i know is stuck. My car hasent run in weeks i seek some serious help please.

Ttt