Fighting myself to start my fast,really annoying!!!!

I could kick myself!!!!!I rev myself up to start this 30 day fast and after most of a day or sometimes even after 2 days I crack up and eat.AAARRGGHHH!!!!Its not like I havent fasted before,but I think this time around I must be scared off by the concept of 30 days.Perhaps I should regard it as a untimed fast,free to go or stop as I please-then maybe Ill stop freaking out.Has anyone tried this approach-and if so did it help?Im going to try tomorrow but just do it with just a generalised goal of improved health.Once numbers get involved,I get obsessive. :)