I would say that I have had some low points after 10 years of retirement, but at least it’s a different flavour of misery.
In my mega bureaucracy, you moved up into inconceivable stress assuming you will leave feet first, stayed put in the middle to be surrounded by younger and younger colleagues and bosses, or retire.
Retirement was at least seizing the chance to try for greater happiness, or at least be miserable in better weather, and I was beyond fed up with 6 months of winter.
My retirement suggestions
1) keep the feet to the fire looking for ways to bring in self employed and passive income however humble, as part of your emotional ecology
2) dial up thrift and financial waste reduction, downsize
3) study and implement diet for longevity
4) optimize your relationship to the medical system. Lean forward on collecting data on your health, act cautiously. Your skill and attitude in this is very much life and death.
5) persist on finding a crowd to have some laughs with.
6) acquire as many dogs as you can manage.
7) force yourself to engage in sports that are active in your area.
8) reduce casual exposure to the news and politics. Learn to read again.
9) engage in actual politics at any level.
10) spend time in better weather and beautiful places, or near your grandchildren if any
11) groom, cook, clean, repair
12) manage your marriage with great attention if applicable. If single, figure out how to meet persons of interest and make the effort.
13) accept that you can’t fix other people’s lives.