I'm retiring also. It took me 2 years to get used to the idea but now I know it's time.
Thirty eight years and what's surprising is I'm still learning this job.
I've been asked to teach tech classes and maybe that will be enough along with everything I've been putting off for years. Like fishing, photography, home projects, wilderness stuff. going to Scotland, my HD, etc.
Would I do it all over again? I'm not much for making plans.
Any advice? Ya, try planning your life.