How come I feel really low on energy everyday and my body feels week?

There may be problem. Feeling low energy is not right. If that is going on for a while and there is no visible problem it is perfect time to have a physician look at you. You may need to have some tests run unless it is clear from your history and exam what the problem is. Anemia, diabetes, obstructive sleep apnea, thyroid dysfunction are among the few for instance.
Consider. Vitamin deficiencies d or b12, testosterone deficiency, even depression. Check in with your family physician.