@juliewot, depression is funny ... I've had a history of depression, but thank God it's been in remission for many years now ... I did a lot of mental work to "prepare" myself for being depressed after surgery ... and still I was surprised by how frustrated I felt during my early recovery ... And then frustrated at my frustration.
A few thoughts that came to me when my mood sank ... One, the period of recovery is still a period disability ... and disability is frustrating and demoralizing. Two, in order to convince ourselves to go forward with the surgery, I think we minimize the length of recovery ... and how frustrating recovery will be ... Also, after the surgery, many of us feel better ... and we sense we're getting better ... but then our brain races ahead and wants us to feel completely better, fully recovered. Part of the mood issue is the gap between expectations and hopes on the one hand ... and day-to-day reality on the other.
I also think there is an adrenaline collapse, and I am speaking more figuratively here. We pump ourselves up for the surgery and for the early days of recovery ... and then the drudgery element of recovery sets in ... slow improvements ... one step forward, one step back ... two steps forward, one step back ... and a surprise step back (something feels bad that we didn't anticipate) ... And we're no longer in the "crisis" mode of having the surgery or being in the early days of recovery.
Frankly, I also think being really "independent" is part of the problem. That's not a criticism of you. Ideally, we'd have people baby us for two months ... bring us food ... visits ... laughs ... stories ... like all the time. Very few of us get that kind of treatment, but I think it would certainly help our moods in recovery. Just my three cents.