Hi Olive,
I'm so sorry that you have to deal with this and that we have to welcome you to the forum. I think you will find this place a life saver. People are gracious and kind and have lots of great information. Never be afraid to ask a question
I can only repeat what many others have said. Everyone's course of MS is different so the best thing you can do for yourself (and maybe the hardest) is not to compare yourself to other people. The number of lesions you have does not necessarily correlate with how mild or bad your MS is or will be. In other words, you can have TONS of lesions on your brain and few to no symptoms or just one visible lesion and many problems.
So I can only give you some hope that there are people out there with mild MS. I also got optic neuritis in one eye as my first symptom. So far I have not had a relapse since diagnosis (I have been on Tysabri for about 4+ years). I walk normally (my balance can be a little bit off but no one notices except when I get bruises!). I can exercise at the gym. I can stay up really late. I can go out with my friends. I can drink alcohol. I can do many things. And I still work full time.
The only thing that slows me down is the heat -- one thing that many MS patients have in common is an intolerance to hot weather, hot showers, hot tubs etc. I get really fatigued and my brain gets foggy and slow when the temperature is high (like 90 degrees or hotter)--my vision gets a little blurry too. But if I get out of the heat and stay cool all of that disappears.
I really understand your fears about being able to continue in a job that requires high intellectual ability and performance. I'm not sure what you do for work but I was deathly afraid I would lose all cognitive function and not be able to do my job. That is still probably my worst anxiety about this disease. I'm a professor, and have published books and articles and given lectures presenting my research in front of large crowds of people. So my work is really my brain and my brain is my work. I need to have sharp faculties to speak in public, teach, and especially to write. So far (knock on wood) I have not been terribly slowed down by any physical symptoms of MS, only by emotional adjustment like anxiety!!
Things like diet, exercise, and therapy can make a difference but they are not cure-alls. It's just a matter of figuring out what helps you feel better. That might take awhile. In the meantime, try not to panic or beat yourself up.
Please keep us posted.