I have been dealing with social anxiety for about 5 years. It has primarily been difficult for me to be around large groups of people, especially strangers. Also being in unkown environments has been terrefying, making me just want to run and hide. It made being at school, trying to get work and going to social gatherings very difficult. Something as simple as visiting my relatives at their summer place was enough to make me just shut myself in my room, as I was scared of the new place that I had never been to before, (despite the fact that the only people I was going there with was my family.) It was extremely annoying and frustrating. My absence in school has pretty much always been crazy high. We are talking 40 days + of absence every year.
I was able to get over the worst of it after a couple of years with a therapist, who helped me a great deal. I still feel it, and it still makes trying out new things terrefying, like starting a new school / university, moving to a new city and traveling to an unknown country. It's scary as fuck, and I have to focus on the things I learned in therapy in order to get through it, but I have come a long way and it isn't holding me back much anymore. I still sometimes find myself hit by panic attacks, though I'm able to keep them in check fairly well.
It's really difficult to give someone in similar situations advice, because the truth is, everyone experiences these things differently. What helped me might just piss off someone else. Social anxiety comes in many forms, and they really only have one thing in common: they all fucking suck.
That being said, my advice would be to try and find a psychologist who you feel really comfortable with. A professional wont do shit if you don't feel like you can talk to them about anything. (After all, if you aren't giving them all the correct info they need, actually coming up with a way to help you wont be easy.) If you can find someone like that, someone you can really talk to and open up to, then it becomes a lot easier. First of all, you have someone to talk to about it, which helps in itself. But you will be able to get help from a professional, who will hopefully be able to figure out what you need to do to get over the problem. Or at the very least, teach you how to keep it in check. It was the latter for me. I didn't need any medication, I simply needed to pull my shit together.
(My psychologist was quite blunt, but that was what made me like her so much. It was so easy to open up to her. Speaking to her about my problems was like second nature to me.)
Don't know if this will help anyone at all, but that's at least my history with social anxiety.