My advice would be to wait two weeks and try another flush. This time try to drink about a quart of apple juice for two or three days, but do not fast. Stick to your favorite low fat foods, just make sure you do stop eating four hours before taking the first Epsom salt. I also suggest you reduce the amount to two teaspoons in the hopes it will have the laxative effect without being a purgative. Epsom Salt is important because it helps relax the biliary ducts and make the flush more comfortable if there are large stones. Another alternative is to drink a bottle of magnesium citrate liquid laxative in place of the first dose of ES and just use the Epsom saltfor your eight-thirty drink. The next morning, use Epsom Salt for the first drink of the day and replace the second (fourth total) drink with another bottle of mag. citrate. This has worked well for me for those times when I could hardly look at the bag of Epsom Salts .
Another thing I would suggest for you is to purchase some EmergenC an electrolyte drink. Drink about three packettes a day for two days preceding your flush and three days after flushing. THis mineral rich drink will keep you from becoming too dehydrated and risking an electrolyte imbalance.
Trial and error is the only way to determine when to stop drinking water. I can usually drink until about thirty minutes before the second Epsom drink, buyt I do reduce the total amount of water I drink as the day goes on.
I hope you will see a successful flush without too much discomfort.