Sorry about the nausea. I had a few rounds with it this time (and I'm not doing the SWF). Hope you feel better in the morning.
As for feeling the fast maybe hopeless... Only if you return to eating EXACTLY as you are before, or worse. You don't have to go raw/vegan to benefit long-term from the fasting. You can just make small improvements in your choices, and your health will benefit. Choose one category, or item, that you want to eliminate from your diet. Try cutting it out for a week, a month, etc. Make sure its something you truly believe you should not be eating, or your resolve will not last. Try to fast at least a few times/year. Do what you're comfortable with, try to make healthy choices a little more of the time, and then enjoy what you do eat.