Anxious when no ones around

I have social anxiety to the point where I can’t talk to people unless a family member is around. I thought I’d grow out of it but I’m 16 now and it seems it’s getting worse. Now I can be sitting in my room and I’ll just panic. Not like I’m scared I just sit there doing my own thing and my heart starts racing and it feels like I’m going to cry.

What is this? Why am I having panic attacks doing my own thing? It’s not even a short 15 minute panic attack. It lasts hours.

Is it because of hormones or something? Or am I just getting way too much anxiety?