What Causes Depression Along With Lack Of Energy And Concentration?

Hello, I have been feeling really depressed, not interested in doing anything except for being on my phone or computer( kind of an escape), not feeling like myself, I feel like there is something really wrong with me, I feel like crying often and am irritated easy, no eneregy, and feel like Im walking through a black tunnel and cant see anything light at the end. Not able to focus (tend to space out). What could be wrong with me?