Well, juicing is easier than fasting with water only. If you feel hungry you should drink juices anyway, even if it is mono juice.
In my experience first two days of juicing are the hardest. For me making a juice every few hours was the challenge. I always felt more alert with juices only. After three days and some planning it gets easier.
Are you using wakame, Dulse, chlorela in your juices? What kind of juices are you making?