Help!! I'm trying to hang brackets for shelving by screwing into my studs...?

I am "workerman mommy" and am trying to organize our tons of toys! I purchased laminate shelves and L brackets to hang on my drywall. I can't believe I actually located the studs and have been trying to put the screws into the studs. I am using 1 1/2 inch screws with an number 10 size head. My drill won's screw into the studs and I am using a manual screwdriver- my hand is all blistered and I still can't get the screw to go flush against the wall!! I tried removing the screws and dipping them in dishwashing fluid and it still is about 1/4 inch away from being flush! I am so clueless-- should I hammer it in the rest of the way? Oh, also my screwdriver is starting to strip the screw! Help me!!! Thanks