Clutch in my truck went crazy and stopped working?

I have a lifted 99 Silverado 5 speed and I was on the highway and the lights that say shift went crazy, it kept saying shift for no reason and then the truck stopped and now won't move. It feels like the clutch is catching but it won't move. Do you think it could be an electrical problem or the clutch went out? It's been sitting at a transmission shop for a couple months and he still hasn't gotten around to look at it yet.

?2016-07-31T11:15:21Z

Find another shop. If they have sat on your truck for two months without working on it, they suck.