Hi Pokaplaya,
It's not unusual to think you're dying. I certainly did when I stopped. The pain you describe is almost exactly as I remember it.
Your consumption sounds about the same as mine was - It took me several months to get it out of my system, and you're in for an "interesting" ride I should think. If you're made of good stuff and you make the right sober choices you will pull through it.
I don't know anything about klonopin I'm afraid, I did find B supplements worked like real magic at removing some of the vice-like pressure in my head at times. Couldn't have managed without them, and would recommend giving it a try.
Expect your mind to play tricks on you to get you into a 'drinking' situation. It might be worthwhile spending a few minutes writing down all the ways and places you've got accostomed to getting a glass into your hand and think of a plan to 'wreck' every one of them while you're thinking straight.
Quitting will fix a whole pile of your problems - It's worth working at, it really is.
Digger said it - Keep digging deep.
Deg.