@OP It took me a little over a year to settle into retirement, but I chose to leave on my own terms. I still miss my coworkers, but most of them are no longer there. I understand your feelings about things going to cr@p. I saw that so many times over the course of 40+ years. The problem, some of the ELT will eventually fall, but it's those left to pick up the pieces who will suffer the most. Try and channel your energy to those individuals.
Take a deep breath, find something which energizes you until you settle into your much less stressful routine. Who knows, at some point they may come crawling back where you have the upper hand as an independent contractor, and you can name your price.
Best of Luck.