Don't take the advice of people who say be comfortable with where you are at now and just wait for the next stage in life. Childhood is such a short period of time and you have the time and capacity to learn that is unrivaled by any other time in your life, don't waste it at a standstill. You should always strive to be the best version of yourself, growing, changing.
I don't know you on a personal level, but maybe hearing my story may help.
I used to be a stuffty student, kind of chubby etc. and then one day during the summer I gave myself a goal. Become better despite everyone thinking I didn't have it in me. After that every decision I made was to service that resolution. I went from mostly threes, bordering on twos in school to fours and fives and got into the school I always wanted to. But this is important: It all starts with finding healthy interests! I would have continued to be a computer addict, if I had not started working out. From there new interests and social activities started coming by themselves and I guarantee you, the more social activities you participate in, the more healthy your computer usage is.
I feel the need to reiterate the fact that I am not you and what worked for me, might not work for you. I just brought out the bullet points on what should work for anyone when applied similarly.
But most of all, if you feel like life is still beating you up and overwhelming you, talk to someone about it. I don't mean on an internet forum, talk to your parents. Or if you feel like you can't trust them or they won't care, talk to your school psychiatrist perhaps. The information you discuss is confidential and he/she won't involve your parents unless you ask him/her to.
