Sky wont show

i was hoping someone might spot where in my node set up i went wrong when trying to set up the sky :eyebrowlift2:

Its also really bright, however thats the first time thats happened. I just need help setting up the sky and the atmospheric glow effect around the mountains. im using 2.62


This might not be it, but try removing the fac amount at the very first mix node, and then try and set manually.