I need support and advice

Hi. This is my first time going on a juice fast. I am planning to go for 20 days. I really want to lose 15 pounds and thought this might help kickstart it with other benefits. I am on day 2 and i find myself a little hungry and sometimes saying oh i cant do this for 20 days. Any tips? Encouragement? Does the weight stay off if you maintain a good diet after the fast?
Oh and i have never written like this before and you mentioned joining a blog???? I dont even know what that is :)