There was chair railing all across this wall and I stupidly decided to remove it. In doing so i ripped off alot of the drywall paper. I was told to put joint compound all across the wall and sand it down. Well I must have used wayyyy to freaking much cause now it looks like this (pic). I thought I could hide it with paint well apparently not. Even sanding it down with a fine grit paper vigorously isn't doing anything. Any recommendation ?

Thanks

 

It's a common mistake to use too much joint compound. Instead of trying to sand it, I would either gut the wall & hang new dry wall or hang new drywall on top of the existing wall.

 

If you want to save the wall, sand it with 80 grit and then apply a skim coat. You want to add just enough joint compound to fill all the depressions and even things out. Shining a bright light on the wall after you've skim coated will help you spot any defects. Do the same thing after you apply the primer so you can fix anything that needs it before you apply the finish paint. Flat paints are more forgiving than enamels.