hours depends on your area. in the west you can work ( I think ) 50 hours a month without penalty to your pension until age 62. from 62-65 i think it is 85 hours a month and from 65 you can work as much as you want without penalty.
i wanted to work for the first year to year and a half after retiring. was offered a bunch of jobs since people knew I worked for UPS.
glad i didn't go back to work. took a hobby and made it into a pretty good side business that we do several hours a day. did you have any hobbies while working? maybe you can monetize that.
we are busier now than when I was working. we enjoy yard work and a couple hobbies. going hiking with the dogs , take day time country drives to small towns for lunch, go to garage sales on weekends , go to the gym , etc.
I think most retirees go thru this after a lifetime of work. At first you enjoy travel, fishing, seeing relatives etc . for awhile but then that all gets old. Then you get into a boring period where you don't know what to do with yourself. You just have to let the opportunities come to you and they will. Before you know the time will be flying cause you are so busy having fun.