Sorry that you are in a down dip right now. Sounds like some sort of change is definately needed, the only question being what?
Please don't let yourself go lower. You know how these sitches work, you need to have some extra energy in reserve for the next down ride dropped on you too. Can you start today with some hard core exercise, give yourself a few days to feel what you feel, then decide to the first steps of your new path to a better place for you?
You know nothing will change quickly, all you need do is take the little steps each day right now, and the bigger picture will become clearer when the time is right.