Depression?

Hi. So I’m posting anonymously for my privacy but I am a 16 year old girl. My life is okay. When I was younger I was full of life, energy. I had friends I hung out with them all the time. But for a while now something is wrong. I cry myself to sleep. There doesn’t have to be a reason. I’ll cry then think of everything in my life that is difficult, sad, upsetting etc. I don’t hang out with friends that much. I lost my appetite completely. I’m tired all the time. And I’m losing interest in things I love the most. I feel as if people hate me. Or find me annoying. I don’t know how to start a conversation with someone. I’m so down all the time and nothing seems to be getting any better. I feel empty. Alone. Sad. My friends don’t see my pain to much. Last night I cried in my friends arms. I just was in my thoughts and couldn’t hold back. It was the first time he ever saw me cry. I don’t know what’s wrong with me..