are you using the pad? if so DONT
also make sure you are squeezing your shoulder blades together..itll take a little practice..
make sure to widen out your grip as well..my gym doesnt have a squat bar and the rack sucks so its hard for me to grip the bar out by the plates but i do go as far as the rack lets me..just be careful ive come close to pinching off a finger or two a few times LOL