Fiona, Knowledge is also comforting. Fear of the unknown is the worst.
That said, are you my twin? My brain MRI result was very similar to yours. My symptoms were almost identical too, except that I had a previous optic neuritis too.
It was the diploplia that got me to the MRI thanks to my eye doctor.
The potential of vasculitis was more concerning to me than the MS because of the prognosis.
I was testing (-) for Lyme also.
Considering the vasculitis potential, I had an extesive rheumatology workup for inflammatory or autoimmune issues. It was all negative.
After two more MRIs (spine) and some other tests, I was diagnosed with MS. Considering the potential of the vasculitis, I was relieved.
I obtained, immediately, the discs containing all the MRIs. I looked at them on my computer. On-line tutorials are available. One cannot diagnose themselves like this, but it did increase my understanding so much.
I am doing fine with most symptoms gone.
Good luck to you.