I cant seem to get through this screen. I am doing what I believe is correct, by going over to the far right to avoid the attacks and then dodge and shoot from that position. I keep running out of ammo before I can kill salazar. Any help would be appreciated.

The snake looking creature that comes from the center of the wall has a yellow, glowing eye. Shoot at it (you'll know if your hitting it by seeing if yellow colored plagas blood is coming out) until eventually the snake will lower and Salazar himself will appear above it. Shoot him as much as possible and keep repeating this process until Salazar dies.

Just go to the way right , Shoot the tentacle thingy 3 times with a Riot Gun , and basicly pwn him good. and the spiders drop good loot for help :3
But though i have a Chicago Typewriter and it oddly only took me 10 secs.