I agree with the above posts
I was "watching what I ate" and feeling frustrated for MONTHS before I really got neurotic about it and made a rule that NOTHING went into my mouth unless I was conscious about it and it was healthy for me and part of my daily plan...and it's still been a struggle for me.
I would definitely recommend joining a plan. I'm doing South Beach Diet and while it's hard at first, it's a very good way to change your eating habits for the better!
Good luck to you. Don't give up, something will click for you.