Some people can go cold turkey. If you can, you should. Those who cannot, do not be discouraged! You just need a plan. Lightening it up, not giving it up, is a solid plan. Many people have made significant improvements in their overall health with this method.
For example, instead of eating the whole slice of the cake eat 3/4 or 1/2, mix your sweet tea with un-sweet, use a little less sugar than normal or try agave in your coffee, ask for 1/2 the cheese on your pizza, have one slice of pizza and a salad instead of two pieces, use less mayo.
These strategies are a starting point. Remember the small, correct choice one day at a time, multiplied by 365 days, is big improvement. Before beginning, it is important to take an overview of the food choices that are a struggle for you and write down your plan to lighten it up, don't give it up. Then share your goal with someone who cares for you, and cares for you enough to hold you accountable.
You can do it!