I’d say it’s less IF and more what you eat within your window, but I am only making an educated guess. Sounds like you need to get more iron in your diet.
> Iron-deficiency anemia, the most common form of anemia, is a decrease in the number of red blood cells caused by too little iron. Without sufficient iron, your body can’t produce enough hemoglobin, a substance in red blood cells that makes it possible for them to carry oxygen to the body’s tissues. As a result, you may feel weak, tired, and irritable.
I’d recommend googling iron rich foods to include in your diet.