How can I overcome my reticence?

My name is Artyom, I am a schoolboy (17 years old), I am engaged and interested in programming, physics, mathematics, photography, journalism attracts me.

My problem is that I can't communicate properly with strangers, I'm afraid to make friends with them, etc. It didn't particularly bother me, but a few days ago I came to a literary evening in Moscow and to a friend's birthday party. It was already a success, I spent a lot of effort to force myself to come to a large group of people. I knew 2 out of 25 people there.

Everything went fine, I liked the evening, but I could not even talk to anyone. I stood somewhere in the corner with a book or phone and thought. Sometimes someone caught me in a group of people who tried to communicate with me, but I gradually disappeared from there, because I didn’t even know what to talk about. Then they gave me a camera, and then I “woke up” and even talked (maximum 2 sentences) with a beautiful girl who actually gave it to me (later I found out that she was asked to do this so that I don’t get bored test-antibiotic.com ).

Then some went to play board games and I went with them. Of course, I did not play, but just sat and was silent. Something was holding me (I was about to leave 2 hours before), maybe that girl. As a result, I was in a terrible mood from the fact that I could not talk to someone, I returned home (though at 2 am, since I do not live in Moscow, but in the Moscow region).

I really want to communicate with them further, they are incredibly amazing and interesting people, but what if I can’t even start a conversation as standard? I must say right away that I have never been the initiator of communication. I didn’t invite anyone anywhere, I always told myself that everyone can be busy or don’t want to communicate with me, and if they want, they will offer it themselves. Everyone tried to communicate with me. There are a couple of friends in whose company I feel completely normal, I communicate freely. It upsets me very much, because of this there is a serious "depression", so to speak. I really want to communicate, but I can't.