Why am i always tired and have almost zero energy?

No energy: Anergia can result from several things, both physical & psychological. Some psychological factors include overwork, poor sleep, worry, boredom, lack of exercise, depression. Some physiological factors are cold/flu, thyroid disease, chronic fatigue or other autoimmune diseases. Consult your primary care doc. For thorough workup.

Many possibilities.: There are innumerable medical, nutritional and emotional conditions that include being tired as a symptom. These range from simple issues to those far more complex. A good checkup and blood testing would be a good starting point.