tpen, I've been there, done that...just what noday said. I remember having such deep "cravings" to call/e-mail/check FB/SOMETHING. I hung on to what the posters here told me, and it was invaluable. I'll always remember anvil's story about thinking about duct taping a mallet to the phone to hit myself over the head with it when I wanted to call!!! I laughed out loud when I read those words, and knew that my pain and craving was well understood. Maybe you could tape the mallet to your keyboard??!
It will pass as you take things one moment at a time. It gets easier...find all the support you can for focusing on YOU...at least, that has worked WONDERS for me.
Breathe deep,
posie