How do I stop worrying what people think of me?

Start taking care of you first and the rest will fall into place. The most important thing to feel better about who you are as a person and as a young man is to be a well rounded individual. Make sure you're educating yourself, take up a couple hobbies, and also volunteer work for a short period of time. You'll find that you're stronger than you think you maybe and you'll have a great time doing something for someone else instead of focusing on any shortcomings that you perceive to have. I cannot say it enough that if you are developing yourself as human being and giving back to the community and the wider world around you, you're definitely going be able to bring something to the table when it comes to having relationships with others. It's too important for you at this time in your life to educate yourself in and out of the classroom and then giving back to the community, once you do that, people are going to naturally gravitate around you because of what they see for themselves that you have to offer.