I Was In A Car Accident Last Wed. The Car

I was in a car accident last wed. the car flipped several times. the ER did CT scans and xrays. there was no apparent breaks, bleeding or severe injuries. I had a bump on my head that has gone down, and I was not able to walk on my right foot. the xrays were clear. however, now I can walk on it but it causes me severe pain. It stays swollen, goes down after icing. now it is swollen to the size of tennis ball? what do I need to do?