I was in an almost similar situation as you when I was 40. I was posted to another department where I was not sure I was going to make it. From having a team to work with, I was suddenly doing everything myself. It was a lateral move, as I didn't get any pay raise. Job scope was drastically different.

But looking back, the posting sparked a chain of (good) events. Because I was not really confident I could pull it off in my new post, I started reviewing my financial situation preparing for the worse case scenario where I might have to throw in the towel. I started investing! Instead of just squirrelly away my bonuses, I started investing in shares that pay dividend to ensure I have cash flow if I had to tender my resignation. The dividends in the initial years were pitiful because the investment amount was small. But grow it did. Now I am looking at $60k dividends pa.

That was not all, I hung on to that job for 6 grueling years and in the process build up a good network of contacts and friends. Something I would not done had I not moved.

In that time, my wife and I also decided to invest in another condo for rental income. That is giving us another $40k pa of income.

And the impossible became the possible. I was brought back to my previous job after that 6 years. This time to lead the team I was working with originally. It has already been 10 years since I was posted back.

Never say never.