You need to go off of caffeine altogether before you start fasting. It took me 3 days of an agonizing headache to do it 2 years ago. BEST move I ever made! Drink lots of water and try drinking herbal peppermint tea. It's also a good idea to go on a fruit and veggie diet for 7-30 days prior to doing an MC. This prepares the body for detox without having such a severe reaction.
Also, if you can't stomach the lemonade, you might consider a fresh fruit and vegetable juice fast. There's more information at the link below. God bless and fast on!!