One of the hardest things that you have to realize is that your friends and family will try to sabotage your weight loss, they "mean well" but they often don't realize that they are sabotaging you and your weight loss goals. They are comfortable with who you are right now. You changing your lifestyle often causes them to become uncomfortable with themselves and it forces them to think about the fact that they might not be taking the best care of their bodies, it's kind of a rude awakening. So they say little things like... oh well you can start your diet tomorrow, or oh you look fine.
The thing is they really might feel that way about you, they like who you are now, that's great! But you don't feel great about you, tell them that. Just let them know that you would appreciate their support, and if they keep sabotaging you tell them a "story" about a girl you know who is having a hard time with her weight loss because either her husband or friend/family member is giving them crap and sabotaging their goals and ask their advice, often times they will start to realize they are also doing that to you, bring up little things that they are doing to you but always say it is your FRIENDS friend. It works for me. My hubby used to say things to me like... I'll miss your fat, or things like that to make me feel like he didn't want me to lose weight and it would always make me quit, this time I pointed it out to him and he said, I didn't even realize I was making you feel that way.
Sometimes friends won't stop sabotaging you, and that's when the hard truth comes about that they might be someone you have to let go, there doesn't need to be a confrontation, just make a note in your head that this person is not a REAL friend and move on with your life. The great thing about weight loss is you figure out who your REAL friends are, but also kind of sad because you realize that some of the people you really thought were, aren't.