It might be helpful to share some more specifics / numbers. Generally speaking, as the volume of training increases the need to restrict calories goes away. For some athletes, making sure to get enough calories is the bigger problem. And for many people, the quality of the food probably matters most. If you’re eating mostly healthy, something like 30% fat / 30% protein / 40% carbohydrates (give or take 10% for any of those), focusing on improving aerobic capacity especially if you have a deficiency will be a big lever to pull.
I have found the diet quality score in Racing Weight  to be useful. The simple act of tracking a few numbers during the day can be a powerful psychological tool to help nudge behavior.