1992 Pontiac Grand Am

I had just got back from a couple hundred mile trip when I started hearing a grinding noise which was random and happened more often when I was accelerating then when I was coasting, the sound went on for about a day when I was on my way to work and I smelled a burning rubber smell and decided to turn around. I just got back up to the 45 mph speed limit and my car just turned off I coasted to a stop and tried to start it again it turned over and revd up very loud (it started doing this around the same time the grinding did) I moved 5 feet and it turned off again this happened one more time then from that point forward my car wont turn over it goes to crank and gets stuck sounds like a skipping cd of the first 2 seconds of a car turning over it sounds like it wants to and its pulling but nothings happening the serpentine belt gets taught in one part and loose in another when you try to start it I tried taking off the belt to hand crank each pulley and the idler wont come off or loosen up I don't see a tensioner on the diagram next to the belt so I figured that was it any idea on what this could be?