My tip is to ignore food as anything other than fuel. I hated brocolli, but now I cannot live without it. I simply sucked it up and started eating it.
Fuel is not for pleasure, or for enjoyment, or something do be eaten out of habit. It's fuel, a source of nutrients, plain and simple. If we must eat something, it's because we need it, not because we like it. Granted, it is difficult and we will always break that rule, but that's the rule we must always strive.
So it's a matter of just doing it - it is hard to do but that's the only way to overcome the mental barriers WE CREATE OUT OF HABIT between us and proper eating. As the nike commercial says, "just do it".
As for the sugar, sugar cravings, specially in the afternoon, that's a sign your diet is lacking in carbohydrates. Not just carbs, but you need more
complex carbs in your diet. Think oatmeal, sweet potatoes. Think small carb-protein-fat balanced snacks such as Zone bars (the best for that particular purpose IMO.)
Judo Olympian, BJJ blackbelt and S&C coach Rhadi Ferguson has something to say on that subject:
I suggest you read this first:
Examples of Simple and Complex Carbohydrates.
And then immediately and without pause read the following by Dr. John Berardi:
The 7 Habits of Highly Effective Nutritional Programs
Then later on, after you have digested the information in the previous links, read the following (also by Dr. Berardi.)
Protein Prejudice
Good luck.