I'm not lost, but I don't know where I am

I have spent the past half hour writing this post, only to be stuck in a cycle of deleting it, and rewriting it time and time again, because it just doesn't reflect how I feel. The problem lies though in the sense of "How do I feel?". It seems like such a stupid question. How could one not know how they feel? My fiance once told me that I'm like a robot. That I don't feel. Of course he did apologise for that comment otherwise I'd be giving him few up-close examinations of my engagement ring if you get what I mean (wink wink). Somehow, as sad as it may sound, I think he has a point.
I've been lying awake in bed, staring for hours on end at the ceiling for the past few nights and I don't know why. I've blamed coffee, indigestion, asthma triggered by the cat, but the truth of it all is that I'm just unhappy. Ok, perhaps I do have feelings. The problem is that I just don't understand why.
I used to get a similar feeling on those boring Sunday afternoons at home, when there was nothing to do and yet even if there was, you just didn't feel like even lifting a finger. The feeling of wanting to change the whole world, add meaning to a mundane life but still find yourself stuck in a office chair typing how bored you are to some contact on msn.
Perhaps I'm just stuck in a rut. Feels like a pretty deep rut though. Just want to leave this behind.