That is not "naturally fat." I will let you in on a little secret, everybody could take all of those drugs and still overeat and gain fat. You are not alone.
There is a reason competitive bodybuilders eat a certain way when in prep, and there is a reason it gets more strict as the show approaches.
Are there differences in metabolism? Sure. But they are a lot smaller than most want to believe.
As you discovered, it is smart to track and weigh your food.
Proper nutrition is the main thing holding folks back when taking steroids.