It is difficult to describe to someone exactly how you feel.
How am I? I'm fine thank you. Well actually I'm not fine; neither am I well; feeling great; top of the world or any such thing but my automatic response would be to say I'm fine.
I find myself stuttering through that answer now with "I'm fine er, well, um, maybe, well no I'm not really" and off we go.
Of course saying you are well is the easiest to get things moving but hardly truthful if the next question is something along the lines of "do you fancy coming out to London for a festive beer?" where upon you have to make your excuses generally and decline and then why.
Of course, the quandary is, how do you be truthful without sounding as if you want to get the sympathy vote - there is no easy answer to this one - if there is I'll post it.