Hissing sound, power loss, late shifting
 

A few weeks ago my truck, usually when started cold, starts at normal speed but as it idles it begins to speed up and a loud hissing noise starts. I can punch the gas a nd it will go back to normal idle speed and the hissing stops. I have also noticed a lack of power and with any load a very late down shifting (it will down shift if I let off the gas for a second).
I have attached two videos. One with it running normal, one with the hissing.

Any Ideas where to start?
Thanks

Did my videos not upload??

Hissing sound, power loss, late shifting
 

Maybe they attached this time.