I was in your shoes bro- believe me I endured some prolonged, unecessary fasts already being malnourished, underweight, and with severe candidiasis in a hope to cure myself- but really the underlying issues were best treated with other protocols other than fasting. I think the effort and will power necessary to do a 7 day Water Fast could be rechanneled into something more effective.
Just my 98 cents. Hope the die-hard fasters don't get on my case :) But I have done long fasts and speak from experience.