Actually I think you have it backwards. Admitting defeat is refusing to take disease modifying drugs (DMDs) which will stop relapses from increasing your disability (assuming you have relapsing remitting MS).
Fighting off the relapses with effective DMDs is refusing to admit defeat. There are now so many DMDs available. Yes, drugs all have the potential for side effects, some more than others. You need to balance out the risk of side effects against the benefits of relapse reduction. If you want the least chance of side effects, go for Copaxone. It also has a low potential relapse reduction rate, but you would still be engaging with the enemy.
If you were prepared to take the chance of greater side effects, chances are you’d get dividends in relapse reduction rates.
Staying as fit and healthy as you can, means taking care of your mother and your business is more realistic.
Have a look at https://www.mstrust.org.uk/about-ms/ms-treatments/ms-decisions-aid At least if you have considered all the options, you are making an informed choice. If you then decide not to take the drugs, you’ll be fully cognisant of the risks and benefits.