I had the same thing happen to me after a contest years ago. The morning after the final show I went to McD's and scored two sausage and chesse
egg Mc muffins. Needless to say after dieting clean for 9 weeks the last thing I needed to do was to throw my body into sodium shock. The swollen angles happened the next morning. They were so big I couldn't tell my knee from my ankle down. It was a stright line down to the feet. Heavy with water I drove to the nearest Seton Medical Center to have them administer Lasix intravenously. After two doses I was pissing the water right out of my ankles and it felt so good!
I'd suggest you do the same as I was worried of having a heart attack because of the whacked out electrolytes.
I went on a cleaner diet after this to allow my body to adjust eating normal foods over time. Good luck!