I am so unhappy

I don’t know what to do. I am so unhappy because I don’t have many friends and i am 16, never been kissed or had a boyfriend and I’m just so lonely. I don’t really enjoy much any more and struggle to see my purpose in life (as cliche as it is, I can’t help it). I feel so ungrateful because I am so lucky, I have a great family and food and shelter, I go to a good school but I can’t help feeling so sad. My mum has finally realised how unhappy I am but is very bad at giving advice. She suggested I see the school therapist but I hate the idea of talking to a complete stranger about my life. How did you people get through your teenage years? Does everyone feel like this?