It is VERY VERY doubtful that even heavy use of your body in work or daily living would contribute to causing MS.

If you had been doing something to severly aggraviate your immune system by constantly being in a situation that would cause you to get viral or orther infections, then I think you could have made your self more vulnerable to getting some over-active immume disorder like MS.

My opinion is that for a few unfortunate folks that getting a series of very common viral infectons can trigger MS. There are very few enviromental causes of MS. The only one that I am aware of is excess zinc exposure.

Stress can aggravate MS and even contribute/cause a relapse for some.

I hope you can find some truely pleasurable/fun things to enjoy and have a more relaxed lifestyle.

jackD