That is a tricky situation. Personally, I find it empowering (that’s the best term I can think of) to be in control of my diet. But then I can definitely understand that it can be tiring & awkward at times, especially with a condition such as MS.
I am not in any way qualified to give you diet advice, & it would be very irresponsible to do so in relation to a medical condition. I would definitely encourage talking to your doctor or nutritionist about it.
A quick search of MS & veganism gets you a few links to a few arguments for & against, talking about how it eases some symptoms (& some advise you to avoid dairy & red meat anyhow), some calling it unhelpful/harmful (some nutritionists are not fond of the vegan diet at all).
I really don’t feel comfortable giving anyone advice on nutrition, & in a situation as delicate as this, I would definitely talk to a trust worthy & qualified source, there are dietitians/nutritionists who specialise in this (but as I say make sure they’re trustworthy!).
I’m sorry I can’t be of any help, but best wishes! x