I am sorry to hear you are not enjoying retirement - so far! - maybe some of the suggestions on this thread will help you.
From my point of view it is the best thing in the world, and I wish I could have done it when I was younger!
I have been retired for 10 years now and the joy of getting up most mornings with a day ahead in which I can choose what to do has not palled.
I am very busy indeed doing the things I love. It is a shame that your job sucked everything from you each working day, so that you have not had room to develop other aspects of your life. But now is the time to start.
This is YOUR time - I hope you find a way of looking at it in a positive light as an opportunity rather than an ending.
There are millions of things you could be doing - some solitary, like reading or study - and some out in the community enjoying the company of others or contributing to the local scene by volunteering in whatever interests you (theatre, wildlife, music, health, education) or just chilling out.
I find it very hard to imagine not knowing how to fill my time!
Passports not in the drawer I always keep them in. Turning the place upside down.