Hey vent away, that's what we're here for.

I can't help you with the work problems, but I think if you can just start by making small, manageable changes in your diet and exercise, you will feel better and maybe be able to get back on track. If you can just start fitting a little exercise into your daily routine, you will likely find that some of the stress is relieved and probably also some of the physical stuff as well. Maybe you just need to start walking for 20-30 minutes every day and cut out one bad food habit for starters. Whatever it is, find something you CAN do and then just start. Once you get started, it can often snowball into more. Good luck!