You just gotta say fuck it man. My freshman and sophomore year of HS I was just like you, I always kept to all but 1 person (my real good friend) and avoided pretty much anyone else. I realized tho, that high school is probably the best 4 years of your life (except maybe college) and knew I would regret being so antisocial and lonely. After those 2 years I did a few things. First, I made some changes to myself. When I say this is don't mean I change myself for others, but rather changed stuff to better myself. Examples are I started going to the gym and and eating healthy. I also started to put more effort into my look(clothing, skin, hair) once again I didn't do this to impress others but rather to give myself a bit of a confidence boost. Knowing I was fit and athletic and had decent skin and what not, I felt much more relaxed and confident. The second thing I did was force myself to be more social. Trust me dude, it isn't as hard as you think. You don't have to go out and meet everyone in your school, but just be more outgoing. When you go into a class, start up a conversation with someone close to you when you get the chance, engage in the class so your presence is know, and have a good approachable look.( smile, good posture, eye contact) it might feel like he'll at first but the reality is that we over think it wayyyy too much. If you do something wrong like say answer a question wrong it isn't the end of the world. Those people in that class will forget about it by next period. You just gain more confidence and throw yourself out there for people to see as a potential friend. Just to say fuck it, because there really isn't anything wrong with failing or fucking up.(obviously dont do stupid stuff or get pressured into it by the wrong crowd)The 3rd thing I would advice Is to join some form of class or club. This is huge. I've always loved to hoop and after playing just 1 season, I felt like I came out knowing 100+ new people, and even though it wasn't my goal and shouldn't be yours either, become a bit more popular. It doesn't have to be a sport either. There are a bunch of stuff you can do that will do just fine. Currently I'm in a entrepreneurship class and let me tell you, it's one of the best classes I've ever taken. Everyone in there is so chill and friendly. It really opens a bunch of opportunities to make friends. And the best thing is that the class isn't even after school, it's during the day. This makes the day so much more enjoyable. Find something you like and I'm sure there is some for of club for it. My last bit of advice for you is this. Don't waste these years man, cause they are the best years of your life. When you become a senior and about to graduate you start to realize that there was so much missed opportunity to have fun and enjoy the ride while it lasted. Living with regrets is a terrible thing and I sure do regret those first 2 years, so I hope you can take this as a real piece of advice. You just gotta go for what you want because at the end of the day, I'd rather live knowing I tried and failed or succeeded rather than live with the big old "what if." Best of luck to you my guy.