I had troubled and stressful years in school. I only felt a sense of self after graduating from school and facing the world. Anyway, I proved to myself that I was good enough for almost everything a guy in his early 20's might be interested in one year after school.
While I was abroad, I lost control over my acne, failed a year due to some silly mistakes and quit drinking, which brought my social life to a very primitive level.
Repeating the year at a different Uni and facing all these crucial changes suddenly started to affect my self-image. What helped was the visualisations I had about a bitter past (it was really harsh at the post school days, I used to cut myself to get over it) and a pathetic future (my dreams vanished). And hence, all the motivation, the power, the imagination, the abilities, the skills, the achievements, my senses, my emotions and eventually my excitement about life was gone with it.
I ended up feeling bad and knowing that I am not doing anything about it. I then turned my mind off. I can’t remember how I arrived at that conclusion or if it just happened. I started to get confused and decision making was very hard, even for something like shopping, because I had mixed emotions about almost everything. I had sometimes irrelevant and inappropriate emotions. I underrated the size of my penis, I anticipated bad marks, I doubted my English skills. I even found it hard to speak to people on the street, and then it was hard to speak my native language!
Then I lost connection with myself. I was just a piece of meat on the sofa, that fellow in the street who smiles to people and feels cold and empty inside.
My feelings were muted to 0, nil, nothing, no fear, no worry, no joy and no aspiration. I was nothing inside, it was impossible to connect with other people or get engaged at an emotional level with an activity or other people’s emotions.
I graduated, cleared my acne, had some hangouts, but deep down I barely felt anything. I remember those days were torn out of the calendar without me doing anything note-worthy.
If you ever feel so, I strongly recommend that you quit any drug you use (even marijuana) and seek a way out, either by counseling, meditation or reality sessions with yourself and loved ones. But get out of your bed and quit listening to negative music, avoid self-harming, masturbation and get rid of negative friends or decrease contact with them. Get a shower, go pick a flower, sit with an old man, play with a child, exercise, take up your hobbies and tell your family to give you some space.
These steps are the basic ones. It didn't work out for me, honestly, but it urged me to seek a way out immediately. The golden rule is that you determine that this situation is temporary and don’t ever learn to live with it. I have made it out by knowing and focusing on what made me alive. Good luck.