B2Y, I can totally relate to this. I stressed over my job for a long time. I had a really supportive boss, too, and he knew the challenges I was up against. Doesn't it help so much to have someone there who will back you up even if you know they don't understand all that you're going through?
I know you'll make it to retirement. Just keep doing what you're doing 'cause it sounds like it's working for you. Everyone makes a mistake at some point - MS or not - so don't beat yourself up over it if you happen to make one.