You relaced the brake pads? If so you're more than likley going to need new rotors and pad's
It sounds like you're pads got worn down to much before replacing them and were causing metal to metal contact with the rotor's. You then changed the pads with new ones.
The vibration is because of the grooves in you're rotor's. You may be able to get by with just rotor's depending on how the pads look.