I think the answer is more like "you are depressed, and that
is normal." Not that I'm calling you names or anything.
If you have clinical depression, you should certainly seek help, but that seems unlikely given your participation in this forum over the last month. I think David's point about the let-down is very relevant - adrenaline building up and then plummeting down can take you for a ride. You have also had a little brush with mortality, something that no one really likes to have thrust in their face, so to speak. And you are having some significant lingering symptoms to boot. You are entitled to be a little depressed.
I have found that returning to normal life is strange, because it seems like I am going about things as if nothing happened, and everything is like it was before, when in fact something rather significant happened, and everything is not quite the same. Realizing that your life has been changed for you, and that you will just have to get used to it, can certainly bring on some down time.
It is one of the reasons we have this forum.
Steve