If you could find a way to white knuckle through the time when you "crash", this really does sound like die-off, and the only way out is through. You do need to go through feeling bad in order to get to the other side (health). Unfortunatlye there are no short cuts, and the worse yo ufeel is a barometer to how badly you need to do this.
That being said, try lots of fresh lemon juice squeezed into water during the day and also try some alka seltzer - that wil help clear out the cobwebs and the lemon helps your liver cope with all the detoxing.