Adjusting to retirement is hard. When the kids grow up and leave you have to redefine yourself. I think too often we do so by putting more effort into our work. Then, one day you are sitting at home with no deadlines, schedules and you wonder what your purpose in life is.
Take your time. It took me several years and then DH retired and I had to redefine myself again. I have learned to sit still. Usually I do handwork or read. But I can actually sit and just think. I've learned to meditate and pray. God will show you ways to have a meaningful life, but at a different pace. PM me and we can discuss more. :-)