I HAVE A PAIN THROUGH MY CHEST TO MY SHOULDER BLADE AND KNECK PAIN

I HAVE BEEN USEING A BUFFER AT WORK AND THE BAREING HAS GONE IN IT AND IT HAS A SHAKE ON IT AS I USE IT AND NOW MY SHOULDER KILLS NOW WHEN EVERY I MOP OR USE THE BUFFER. I HAVE SO MUCH PAIN IN MY SHOULDER AND THE PAIN IN THE FRONT OF MY SHOULDER FEELS LIKE A SHARP SEAR GOING IN AND COMING OUT OF MY BACK AND THE PAIN IS THERE ALL THE TIME. HOW DAMAGE HAS BEEN DONE?