I woke one morning in 1999 with double vision. I was TERRIFIED that I had a brain tumor!
After an emergency trip to the Dr (and reassurance that I didn't have a tumor), I was sent to an ophthalmologist. He was kind and examined me, was concerned about my fear, and asked a few questions. The last question was "Have you experienced any numbness and tingling in your extremities?" Well, I had. I had been seeing a chiropractor for numbness and heavy legs.
My ophthalmologist paused, then said I needed and MRI. He gently told me it was likely that I had MS. SCARY!!
Long story short, the MRI was all MSsy; my Dr. sent me to a neuro; the neuro diagnosed me with MS based on 16 symptoms I presented. All of this happened within two weeks.
I know many (most of you) waited for months and years to be diagnosed, but I did not have to do that- I blundered into the right ophthalmologist's office and ended up with a diagnosis instead of years of fearful guessing. That is blessing number one.
Number two is this: My eyes are stronger now, so I can control the double vision as needed. When my vision gets harder to control I know to check myself and take it easy (and call my neuro!)

All my best wishes to you during this trying time. Good luck to you and may you find many a silver lining!

-jill