>>1 >>2 is right, hikikomori is a serious description of someone who never leaves their house, oftentimes it's meant as a harsh insult.
Anyways, being a shut in isn't all that bad. Real people tend to suck. But being a shut in doesn't pay your bills. Keep at school and find work or even college afterwards. Limit yourself on how much time you can spend on your laptop, even get your sister to take it away from you for a portion of the day, it'll take some time to get used to but keep trying and like any other addiction, you can beat it. :3