Based on my experience with 100-160 people everyday, I would take a very good guess that you are not eating enough.
Our bodies need energy ie: FOOD to function. If are not getting enough energy, you will feel tired all the time.
For bow, I would highly suggest eating more foods like whole grains, nut and peanut butter. PB is a good source of fat & protein that will give you some good energy. Lots of fruit also.
PLEASE MAKE SURE YOUR DIET CONSISTS OF AT LEAST 50% CARBS. If you by chance are not getting enough carbs, you FOR SURE are going to be tired and fatigued.
Pick a 'good' food day that you had recently and write it down and send to me. I will be happy to look at it for you.
GO EAT & GOOD LUCK!
In Good Health,