the leg is big concern find an MD that will take it seriously.
You should get a second opinion preferably from a medical doctor. Perhaps all that is needed is a compression sock but maybe there is something more serious.There are a number of reasons for a rash accompanied by swelling a doctor can diagnose and treat the underlying problem. The same applies to your low back pain as it depends on where the pain resides - left, right, middle, upper region or closer to buttocks, and so on. Good luck