Use an online nutrition tracker for a few days and see how you do on the 31 Essential Nutrients. Then increase the ones you lack. Since weight is not an issue, you will probably see a good increase in energy once you start getting optimal amounts of these items.

For each one, you can go online and find the "best" sources. Just try one or two at a time and then go on as you succeed. Once you are getting all this nutrition, the desire for crap food reduces. In your case, I would not worry about it too much and you will see it reduce anyway.