Oh Kate I do so feel for you. I broke my arm last year and absolutely slept for England for the next month or so. GP said it was a mixture of energy needed for healing, and trauma to the body, which is extremely draining. I didn't feel at all traumatised as it luckily wasn't too painful and I had a lot of help and kindness from friends and family, but even so I was amazed at the exhaustion. My hair also thinned for a while - again, trauma it seems, the body just does not like it when it is battered about. Chin up - it won't last that long