As someone who essentially had to retire prematurely due to a variety of personal circumstances beyond my control, despite the fact that I loved my job and would have preferred to have kept on working, I strongly suggest that you find something constructive to keep you busy.
For awhile I had no idea what to do with myself and ended up getting really depressed. As nice as it might seem to just relax and do whatever you like all the time, it just doesn't come naturally to someone who gains satisfaction from a good day's work, and ultimately just makes you feel terrible.
Nowadays, I work from home as a Data Entry Operator, mosly pro bono, because it gives me something familiar and constructive to do. I've also established a daily workout routine and have become something of an amateur bodybuilder over the past few years. So I'm technically retired, but I still keep busy and I'm honestly in the best shape of my life, emotionally, psychologically, spiritually, and physically.
Retirement doesn't mean that your life has to slow down to a stop. Find things to keep you busy which bring you the same satisfaction that work brought you before, if not more so, because now you're free to pursue the interests that you couldn't previously. Furthermore, I highly recommend getting into a daily workout routine, not just for health but because the physical exertion will keep you feeling young/active, and nothing helps your self-esteem like honestly being able to say that you're in the best shape of your life post-retirement.