If you have access to getting a colonic done, I highly recommend it, and if you can't then maybe an enema. It won't have the same effect, but it will help. My second flush was bad like yours; it took me 2 weeks to get over it, and I finally did. I think it is because so much stuff comes loose that your body can't handle the detoxing very well. And some of it might be stuck in your bowels.
My third one went a lot better and I felt better within a week. Today I am doing my 4th one.
Keep on trucking!