Loss of appetite

I really don't know if it's the stress, current state of unhappiness or some actual sickness that's been gnawing away all of my appetite these last few days.
Neither alternative is very heartening since I find it gravely disturbing that me feeling like a discarded toy may actually have a real physical impact on my poor poor body.

I find myself thinking of Jake Gyllenhaal's character in Jarhead, I usually have a standard solution for when physically feeling like a piece of crap (no will to eat = no calories = no energy). For example: If sick, then rest and eat as much as you can. Go back to the gym, take it easy and slowly recover.
But now, I feel sick because my current state of min reflects badly on my body. I want to scream at my pituitary to stop stimulating the release of stress hormones but I just can't bring my psychology around to complying with my rational state of mind. It sucks not to be the boss inside ones own head.
Now I've felt depressed before, but never like this, and it scares the shit out of me. Still I'm not worried that I won't recover and end up as a sad broken shell of a man. It's not that bad.

What I'm saying is simply that I think I start to understand how people can lose the will to go on with their lives in any direction. I understand how someone might just lay down and give up.
That state is still far far away for me personally. I'm just saying that I've glimpsed a fraction of it towards the other end of the valley next to the future sunshine I hope for.