Talk to a professional counselor, Licensed Professional Counselor (LPC).

You

100% endorse what (https://www.gainrep.com/profile/ojok.issa ) advised. I would also say that you can try mindfulness and quick grounding... techniques. Let me know you would like to schedule a session to discuss a bit further.  more

Social anxiety disorder, you do fear to be in public openly
So you can practice to be in public while you are with your close friend you trust, then... slowly by slowly you can try to do it alone.  more

I feel like I m a lone and when I m that moment I don't feel happy

Thank you.

therapy (especially cognitive behavioral therapy or CBT), medication (antidepressants or benzodiazepines), and self-help techniques