It is completely natural to feel this way. But trust me it is the best thing we could have done for ourselves. As for being afraid of failing, the advice I really took from my nutritionist is after the required appointments are over to come back and see them as soon as you notice you are gaining again. She said it is a lot easier to fix 5 pounds than 100. Be honest with yourself and as soon as you suspect you are forming old habits, go see your support team!
Also don't forget to take a before picture and keep that as your motivation!
Surgery: 6/26/13 HW 370 SW 331 CW 299