Coffee is not a diuretic but more like a laxative. It usually causes activation of certain enzymes in the liver that increases peristalsis. Tea (depending on the type) is more of a diuretic.
You could be allergic to coffee or something in your coffee.. Try switching to regular tea and see if that helps your edema. Don’t do salt water flushes if you have edema. No Master cleanse either.
Has your doctor checked your potassium level? I don’t have much time today but will write to you soon. Meanwhile let me know how you are doing.