Macros, Calories, and Energy..help!

Alright. I'm trying to keep my calories low, between 1300-1900 depending on workouts and also work schedule so I have enough energy to get through the day. I'm also trying to have macros of 40% carbs, 30% fat, 30% protein. I have no problems meeting my protein goals, which is my priority, but my fat is always low and my carbs high.

What are the consequences of this other than more immediate energy? How can I change this without just adding calories?

Thanks!