BF like you I have come to dislike flying more and more.
However, I do not think that disliking it would be the real explanatory factor in ending a marriage. There are strategies and good 'short' therapists who can help with this anxiety. That is, they focus on the emotions around the problem rather than doing full therapy, It's been around a while, and it isn't Cognitive Behavioural therapy
The fatigue is probably associated with the stress of dealing with MLC and a new job. Plus we are all getting older. My energy levels are definitely not what they were.
Even now I sometimes have to put myself back together again, and I know widows who have the same problem. We lost something pretty big in our lives.
I admire your understanding towards your h, but would suggest you do not go overboard on this one! It might explain but not really justify what he has done.