Get your thyroid properly evaluated. A sub optimal thyroid can cause fatigue, as well as weight gain, dry skin/hair, and constipation.
Ensure that you drink enough water (aim for the amount of water in ounces that equals half your body weight in pounds. Ex. A 150 pound person should drink at least 75 ounces of water daily)
Get adequate sleep. Go to bed at a time that gives you enough time to get the rest you need. Keep your bedroom quiet and dark at night. Ensure that your Progesterone and Melatonin levels are optimal.
Get your Testosterone level checked. Both men and women need an optimal level of Testosterone in order to feel their best.
Eat whole foods throughout the day–a lot of vegetables and healthy protein. Eating foods with simple carbohydrates and sugars can make you tired, as well as cause weight gain and other health issues.
Unplug! A constant bombardment of information and demands affects us and causes fatigue. Turn off your phone and other electronics at night and whenever you can. Avoid watching news or other negative influences–there is no reason to bombard your brain with this stuff. This will reduce your cortisol and help you to relax and sleep better.
Have a purpose for your day. Having something to strive for gives you energy. Plan fun events to look forward to.
Have your nutrient levels evaluated. A lack of certain nutrients can affect your energy level. Many patients respond well to B complex injections, however there are other important nutrients.
Take deep breaths regularly. Breathing deeply and correctly helps you to detox mentally and physically. Yoga or Tai Chi can help you with this.
Allow yourself to rest when needed. Stop pushing yourself to do too much. Avoid using caffeine (soda, energy drinks, coffee, etc) to falsely boost your energy. Depending on these products for energy puts you on a roller coaster of ups and downs.
The bottom line is that you must be aware of what you are doing on a regular basis and get your hormones, sleep, nutrients, etc optimized and you will have the energy you desire.