I would definitely advocate not going cold-turkey on caffeine, especially if you currently consume a fair bit. Got to bring that down gradually or you get some pretty unpleasant side effects - the headaches in particular can be awful.
I'd be an advocate of cutting out, or at least cutting back, on the booze. If nothing else, you're likely to get some much better-quality sleep which gives you a fighting chance the next day. Exercise helps in that regard too, even a walk at some point of the day is beneficial for more reasons than just the moving around.
But then, as others have said, taking advice from a bunch of internet twats is never preferable to discussing with people who actually know what they're talking about. Hope you're soon feeling better, Ingo.