Neither are quite right. You would try to eat A little more healthILY than you had DONE. Word order in B reads a little easier.

Kelly's answer is the best. healthily is weird Either of these are also correct and common: I am trying to eat a little healthier to make the start of my day more awesome. To make the start of my day more awesome, I am trying to eat a little healthier. Though trying is correct and very common, it is weak, mediocre language. If you've seen Star Wars, the character Yoda says, "Do or do not. There is no try." Since you wish to make your day awesome, as opposed to being mediocre, you should use strong, empowering language: I am eating healthier to make the start of my day more awesome.

These options are all a little awkward. You may want to try something more like "In order to make my day more awesome, I am trying to eat healthier breakfasts."

To make the start of my day awesome, I am trying to eat a healthier breakfast than I have in the past.