Mathew:
i questioned 'AF', i feared it somehow becuase it made me lose the idea of the bedrock of the meditative path and it unsettled me, i experinced depersonalisation. (existensial meaninglessness), i got delusions of its correctness and decided i knew it all (haha) and engaged in the self perpetuating argument. then i reasoned with it. then i felt relatively normal and just happy to be out. then i worked through things gradually and things came to me, little messages of logic and sense all around me, some of it was from watching alice in wonderland which follows this theme of depersonalisation and questioning. there is an interesting koan in it which will help if you can answer.
Something similar happened here also. I got particularly apprehensive and scared that I was accidentally working towards AF without meaning to, because the clarity of the senses has become very pronounced, as if a whole layer of filters has been removed (which is nice, actually, but which I didn't know could result in having one's affective faculty pulled out).
The only relief I find for the lonely despair thing so far is when I (accidentally at first) engaged in some sort of AF practice, as when I look around and see that everything is in fact gorgeous, I am lead into a sort of peaceful wonder, and that helps me make it through the day. And I have to admit, such a practice does enclose its own very powerful logic, and it exerts a tremendous pull (towards what I would guess is utter self-dissolution into the world).
However some of what you vaguely described, particularly a lonely despair, which is also a sort of unfeelingness, could be what I seem to be going through, as it seems like a good name for the overall tone of this part of the path. It is as if one is hurt that things turned out to be the way they are, or appear to be, but does indeed rationalize repeatedly that it is simply the way it is, without even seeing an alternative since the logic sustains itself fairly well (even in real time), a certain "I've stopped believing santa claus" (but it was soo nice!) sort of mood. However, I can get out in the garden and enjoy things, since at least the flowers are, indeed, very pretty, and that brings genuine comfort, so maybe we are talking about different things?
Please be more thorough. If you want, we can talk through skype, my skype name is bruno.loff .