Yes, your water intake is kind of high... If you would be able to bring it down to 3 liters a day, you would probably get rid of the edema. Also, I can't tell exactly how much sodium you're eating, cause I don't know if there is salt in your chicken/ egg whites. Supposedly 500 mg a day (or less) of sodium would be ideal, you're at 700 mg per day (soup), plus any other sodium in the chicken and egg whites. You need to eat twice as much potassium as sodium. The recommendation for potassium is 4700 mg but that is mainly because most people eat at least 2300 mg of salt a day, which is WAY too much. If you eat 700 mg of sodium a day, you need to eat at least 1450 mg of potassium. I don't know how much potassium you eat, but maybe you can find out.
It is also best to spread out your water intake, so sip on your soup all day long instead of a lot at once if you can. If you ingest too much water in a short amount of time, the excess water will not stay in your cell walls>>> edema. Potassium helps keep body fuids in the cell walls.
I am not a doctor but I would recommend for you to eat leafy green vegetables/ lettuces or other raw produce to get enough potassium (and other minerals, vitamins), and some fiber in your system. You may want to also take a potassium supplement, and always have some in your purse for emergencies. Meat does contain potassium but if you eat under 800 calories a day, you most likely will not get enough. Just don't take more pills than is recommended!