Just to put a slightly different slant on things, you say your wife has only recently been diagnosed, and is well at the moment?
I think you might have hit the nail on the head when you admit it is your own anxiety that needs addressing.
MS in NOT a life-threatening condition, in the vast majority of cases, and certainly doesn’t sound as if it is for your wife at the moment.
It may not be great for your wife’s confidence or independence to foster the belief that she is too ill to be left for one week. She still very much has a life to lead - as do you.
I do know MS can affect people very differently, so perhaps I’m underestimating how severely your wife is affected. But if it’s any reassurance, I can tell you I have continued to live alone for over two years since being diagnosed, and absolutely nothing has come up I couldn’t handle, at all.
If somebody suggested I wasn’t safe to be left alone for one week, I’m not sure whether I’d laugh, or feel quite miffed about it.
Also, MS is NOT a terminal disease. You and your wife can expect to have about the same number of years together as any couple where neither has MS. So the feeling that you cannot spare even one week, because her time is so limited, is not an accurate reflection of reality.
I would suggest you go on the trip. For every person who is diagnosed, and their nearest and dearest, there’s a first time for things. A first time to go on holiday, first time on a night out, first time to be left alone - a first time for everything they wouldn’t have thought twice about before the diagnosis. But the only way to overcome the feeling that all these perfectly normal things are now somehow dangerous and off-limits is to go ahead and do them. Otherwise you’ll never get the confidence that you can do them, and be fine.
Playing devil’s advocate, suppose you were very unlucky, and she did have a relapse in that one week? Is there any help she would need that could positively, absolutely, ONLY be given by you? Or could it be given by anyone with commonsense and the number of her GP or local MS clinic? A relapse can be nasty, but is very rarely a life-threatening emergency, in the manner of a stroke, heart attack, or car crash. Many relapses don’t require hospital admission or treatment at all, and the advice is just to rest at home. There would be ample time for you to rearrange your flights and make your way home: there’s nothing that requires you to be there in an hour.
What does your wife herself think? Is she anxious about you going, or is she confident she’ll be absolutely fine?
I think if you do it the once, and it goes fine, you’ll be much less anxious about doing it again. I don’t think it’s a great idea to think about jacking in your job so soon after your wife’s diagnosis. That could be a bit of a knee-jerk reaction. See how it goes for a while first. You can’t yet tell how frequent or severe your wife’s relapses may be. If time shows they are neither frequent nor severe, you might find you’ve turned your back on a blossoming career unnecessarily.