Dee, don't hate yourself. What you're talking about is being human! If you were perfect, the rest of us wouldn't dare talk to you! Seriously, I do this to myself too - beat myself up about making mistakes.
The two best bits of advice I've been given are:
The people who don't make mistakes, don't usually make anything much - i.e. people who try risk failure, but its better to try than not to.
The next bit was to do some work, affirmations etc. to boost my self-esteem, since I was far more likely to stick to something that was good for me if I felt I was worth it and good news now, not only when I got thin. And they were right!
It would be nice if it were a straight, easy journey, but I think its rarely like that.
Keep the faith and know that you're worth it.
Best wishes, Jay