I also feel like I'm snapping, but today, I forced myself to do the opposite of what I felt like doing (lying catatonically on the couch). I forced myself to eat something, get up. it worked eventually (after many attempts and counting to 3). once I got up, i actually started to feel a little better.
But, I am by no means 'healed' so maybe i'm not a good person to be giving advice right now....