Need help wiring two lights from a switch at the end
It's your ground wires. They're on top.

They're biffing onto a neutral or hot terminal.  

Also, you need to use the #10-32 screw in the steel box and put a pigtail on that, and join that to the ground wires.  Alternately you could use ground clips to attach to the sides of the box.

The key here, however, is to push the grounds into the back of the box behind all other wires.  You should do this as the very first thing, and then never think about them again.  This will greatly aid troubleshooting; often people wire grounds last after testing, and discover connecting grounds breaks the circuit. This leads them on a snipe hunt looking for a ground problem, when it's something else.   

The next layer above grounds is everything that doesn't tie to the lamp, i.e. those black bundles one of which will soon be a black-white-marked.   

Then finally the wires go in that actually attach to the lamp socket.  That should solve it; there's plenty of depth in a 1.5" octagon box to keep the grounds far away from the socket back face.  

Your switch loop is wrong

Code requires a /3 cable for a switch loop so neutral is present for smart switches etc.  Use of a /2 switch loop is allowed if changing the cable is easy without tearing apart any part of the building, i.e. Conduit or unimproved work.  However you must do BOTH these things: 


Use the white wire for always-hot, not switched-hot as you have.  That is so the white wire will definitely test hot at all times, and it's not likely to be confused for a neutral.  AND 
Mark both ends of the white wire with colored paint, tape or shrinkwrap.