I’m like Theorising. I’ve had undeniable symptoms since I was 15 but didn’t get a diagnosis until 54. I learned early on to stay out of direct sunlight, stop taking hot baths, and then I gave up long-distance hiking when I was 17. Other than that, it didn’t affect my everyday life much beyond needing to rest a little more than other people.
I went to trade school, worked full time for 34 years, commuted 112 kilometers a day for half of those, raised a family, did the house and yard work. It’s only been over the last 2 years that I had to quit working, but I’m not in a wheelchair, only occasionally use a walking stick, and can live alone just fine.
MS does affect everyone differently, but don’t write off your life at this point in time. Yes, you may find things that you can no longer do (climbing Mt. Everest is probably one of them), but then you just find other activities to fill in. The important thing is to focus on what you CAN do. Learn your limits and adapt to them as they occur. Develop a routine and figure out when you can push yourself and when you can’t.
I’ve had a very full life and am happy where I am now, in spite of legs that don’t work very well now. You should have many years before your life changes very much.