I believe this is the same post you posted on the Water Fast forum. As I stated there as well... 100 days is to long for someone of your size. Please read the replies that were given on that forum, they were good information.
After a few days you will quickly realize that a goal of 100 days is far to extreme for a first time fast. Very likely fasting for 100 days at your size would kill you. Just being blunt here, but common sense would tell you that.