Alisonl - you are very brave!! I've been thinking about you a lot. Sorry you had a bad experience. Please try again (when you're ready) but perhaps do less quantities of everything. Did you do the week of apple juicing for prep? Also, in the week leading up to it, taking a tablespoon of olive oil with a tablespoon of lemon juice in water every day helps too.
Can a friend stay with you when you do the flush to help you if you need it?