It's the craziest thing -- you can be obese and miserable and decide to be pro-active and make a positive change in your life and suddenly your loved ones / friends decide that's the time to start tempting you. It happens so regularly when people try to improve their lives that's it's got to be some sort of wacky subconscious trait in humans. People don't like change - even if it's for your best.
I decided to do my first 30-day juice fast after finding out my blood pressure was at stroke level (130/110). I had no desire to get on medications. Within 7 days, my BP was 110/70....the only thing different was the juice fast.
As for the sugar, switch to Stevia. Do a Google search and read up on the benefits of it - it helps regulate the blood Sugar and is a natural product from the Stevia plant that grows in the rainforest.