If your job is halfway tolerable, and you’re healthy, don’t retire!!
I sold my company at the end of 2012 and I have regreted it ever since.
I always think of Bear Bryant dropping dead a few months after retiring.
Did you have a life outside of your work? If not, I recommend finding what it is that you like to do, then doing it. Maybe start a new company? Find a hobby or a volunteer activity that you enjoy. What was it about your job that motivated you? Hopefully it wasn’t just that it filled your time. I hope you find what your looking for and I wish you all the best. God Bless.