Every addiction always starts with the mind before our body gets hooked. Another thing is that we are creatures of habits.
Because of that I strongly believe that if we want to change a habit, the way towards a permanent change is to add a new healthy habit little by little, instead of going completely cold turkey with the old unhealthy one. That way our mind will not start to protest and the transition will become smooth.

F.ex.: Instead of cutting out all of the sugary products at once, try to add a little bit more of fruits and berries in your diet. Let your mind and body get used to the change. Then a little bit more. If you love chocolate – try to gently switch to dark chocolate.
Your mind and body will automatically follow the new direction, and you will avoid emotional turbulance that usually comes if you cut it all out at the same time.

It seems to me that you are pretty aware of what you want to change in your life, and that is one powerful first step you got right there! Congratulations, you’re on your way to success! 🙂