go back with a good mid grade pad on it, i use ceramic pads and they don't squeal or make any noises, they cost more but are well worth the money,and they also stop a lot better ,you,ll notice the difference as soon as you install them,good luck.
it is most likely worn out brakes or cheap brake pads. the best way to go is ceramic brake pads. don't get semi metallic, those tend to squeek a once in a while.
lets just hope you didn't wear out the brake pad to the metal. the would mean you would have to resurface your rotors or even buy new ones...but that's just worst case scenario.
good luck though.
