I think I have social anxiety but I haven’t told anyone

Ive always just seen myself as very shy however during exams it started to get in the way like i couldn't cope with answering questions in front of the class or speaking to a teacher its like i try to speak but i physically cant because I've constantly thinking about what people will think of me. I've had occasional melt downs possibly panic attacks but nobody seems to get the hint that I'm very anxious. the problem is I'm too anxious to tell anyone and recently i haven't been sleeping because i have a big school trip coming up and like 5% of me is excited however 9 5% of me is completely petrified and i don't know what to do.

i was the same way in school. i would sweat and feel horrible.do u have a school counselor to talk to? YOU NEED TO GET SUPPORT with this. the talk is completely confidential by law.
do u have family u can talk to?
THIS IS VERY common. millions of people have social anxiety!
The best thing I did was go speak to a counselor. They are very supportive and can help you manage this. It’s very difficult to try and help yourself alone. You need some direction. You can get it under better control with help. Don’t be shy about this because you deserve to feel better. counselor see this every day!
take care of yourself

I know how you feel, I was exactly the same in school. I remember once having to do a speech in the front of the class and I know I had to of turned white, thought I was gonna pass out, and nothing would come out of my mouth. I was shy around pretty much everyone, even groups of friends sometimes. I do believe it followed me into adulthood because I never told anyone, or got it treated and it led to drinking just to be outgoing and that is not the way to go for sure.
You definitely as Jan said should talk to your counselor and explain what you’re feeling and what is bothering you and get some guidance from them. Nip it before you get older like I did. If the counselor isn’t much help, I would mention it to your parents, I’m not sure what your relationship is with them but it does help to let someone else know how you are feeling, to get it out in the open. Trust me don’t be shy to ask for help, too many of us hold it in fear of being embaressed but it is soo common you would be surprised how many others feel just like you do.
Best Wishes!