Even though your symptoms do mimic MS there are a lot of other possibilities out there that carry these same issues. Some as serious as a brain tumor or ALS to a vitamin D or B12 deficiency easy fix....
For what it's worth here's my take. Can MS "burn itself out"...No. Can MS "plateau"...Yes. Is MS "always progressive"...No. Am I or could I be "wrong"...absolutely! Whether or not your MS progresses...