Sally,
I know your body is dealing with a lot, but the single most surprising part of my THR was my level of exhaustion. I was shocked how it sapped the energy out of me and for how long. And I know that you have had your body battling an infection and the antibiotics can drain you as well. Sorry that it doesn't help make it any better...just hoping knowing that you are not alone in this might help a bit.
I would steal a nap (and usually set wake up alarms for things I needed to do) whenever I could.
Z