I recommend reading Elain Delacks - They said it didn't make 'cents'. Though she encourages using a compounded drug - its not conventional MS drug treatment, and has allowed her to stay symptom free for years. The same treatment was used in 1950's by a Dr Hinton Jonez, with much praise of success, but the information has been buried and not endorsed by the MS Society.
Alternatively, have you read much about mercury, lead, aluminium poisoning. It may be suttle, it might not even be from Amalgam
fillings, and could well easily be from something unknown, but there is a strong possibility that you are toxic of these substances. A good test is a Urine DMSA challenge test. If it proves you have high levels of these toxic chemicals then you can rule out the cause being anything else until you complete chelate these from your body using either DMSA or alternative chelators. Don't do this test though if you do have mercury fillings as its likely to pull more from the fillings into your body causing more damage.
Once all these have been ruled out, the final and most likely cause is hidden parasite
infection. Look into Hulda Clark
treatments, ozone therapy, and zapping - see Ken Presner Ultimate Zapper and other bio resonance therapy treatments.