At least you got to plan for it. My last day at work the owners walked in and said it was time for us to part ways. I just about quit a month earlier, but my wife begged me to just retire, yes, she begged me! I worked for that company for ten years with no issues, then they hired a manager in between me and the owners and we didn't see eye to eye.
As for going back to the 9 to 5? No way! I can not imagine it! I have plenty to do around here, house projects, projects in the shop tearing apart stuff and rebuilding. No plans to go back. Best part is I can dress 24 hours a day if I want.
My wife is jealous and is planning to retire soon.
you might fine the desire to volunteer somewhere for a few hours a week, but be careful, some of those volunteer deals are lie work!