Post Race Letdown/Depression

Has anyone ever experienced post race letdown or depression? If so, what did it feel like for you, and how did you overcome it?

I've been clinically depressed before, and this doesn't feel like that did. Last year I ran my first half marathon and afterwards I got lazy, but I don't remember feeling depressed or down in anyway. A week ago I ran my first full marathon, and now I'm just off. I don't have much of an interest in food, my boyfriend says I've been short tempered, and I've had odd aches/pains (like a side stitch while sitting at my desk, or achy joints through my entire left hand).

I hope that next week I can start working on getting back to running and that will pull me out of this funk.