Ok, give yourself credit where credit is due! You've done so well so far, in coming all this way and no cheating...
Don't let them put negative thoughts in your head. Try writing down a list of as many reasons you can think of for why you're doing this diet. Then write a whole long list of mini-goals so that when you do achieve them you can reward yourself with something nice!
Above all, keep focused. If you stick to this plan 100% you will lose weight. Guaranteed. After you've lost the weight, worry about it at the time no use in worrying now! You'll find a way to maintain weight, as long as you can throw off those negative comments. Do it for you and not for others, and when others see the change for themselves, they won't make negative comments then.