I may have social anxiety

I didn't even knew that I had social anxiety. It seems so normal, seems like extreme shyness. I had no idea that it was something like this. I only came to know of it's existence when I searched about it on the internet. I always feel so overwhelmed while giving presentation or even talking to a stranger! And sometimes when I am walking on the street or even in a large crowd I feel like people are staring ate me. It's so weird and I don't know how to cope with it. I hope one day I would over come this unusual fear.