I am so sorry to hear that you have been having difficulty with your kidneys. It is promising that your biopsy
was unremarkable and that you did respond well to the steroids, but it is certainly disappointing that you had such a severe response to salt. At this point, the key thing will be to establish a clear diagnosis. That may mean that you need to seek a second opinion from a tertiary medical center. This is likely to be affiliated with a university hospital or the equivalent. If you have already done this, there are several medical centers across the country that specialize in seeing those patients who have been treated unsuccessfully at other sites, and you could consider visiting with a nephrologist
at one of these locations. A few of these will have chat lines where you can submit a specific question with some of your data prior to making an appointment, so that all of the necessary information is provided and your appointment can be as useful as possible. As far as your prognosis, it is difficult to say what to expect based on the information that you have provided. Please speak further with your doctor
to establish what your diagnosis is and what you can expect moving forward, and best of luck.