2006 Chevy Silverado Transmission wont work

I have a 2006 with 68k on it. The transmission quite working today. I was taking a turn to climb a more steeper hill. The truck went to shift down for more power and all of a sudden the truck hit the rev limiter. No load noses and its never done this before. I have drive third second and first. The only thing that works is first. And second will as well but acts funny and makes a horrible noise. Drive and third act as if its in neutral. Reverse works fine. I was wondering if this is a simple fix. Or could the transmission possibly be done for?