Hi There, I Had A Root Canal Opened Up And

Hi there, I had a root canal opened up and cleaned out on friday 1st October. there was an infection of some kind on my bone or at the base of the root canal which was done many years ago. So the crown was removed and the root was cleaned out. I have been on pain relief since friday 1st and eaten only liquids. the swellling has gone down but today there is a swollen area in the gum around the outside of the the tooth and a white spot on it and I don't feel well. what's happened? How do I treat this?