Congrats on the ZERO...
Sounds like you're an early morning person like I am...I finnaly figured that walking between 5 and 5:30 am works for me...Trying to do it after work never happened.
I think tiredness has more to do with age or other issues then post surgery. On average, I go to bed around 9pm...I have some issues with my vision...If I read a ton of stuff during the day, I'm worn out when I get home...
You might want to google -> energy foods
and see some of the things you can eat to get a natural boost.