Today i fell on my tailbone/ lower back while doing squats, i think it's bruised. what should i do to treat this injury/ relieve pain?

Ice and don't sit : The tail bone is a sensitive area of the body but not a critical part of the spine. When injured one needs to avoid sitting on it. This a doughnut type of a cushion helps as wellas icicng in the beginning. As time goes this becomes easier but they can last sometimes for weeks. If the pain is severe you need an x-ray to make sure that you do not have a fracture.