I’d suggest seeing your GP first and asking for a referral. As TheGal mentioned, it sounds like you need intensive therapy.
I’m unsure of your age. You mentioned oral presentations. Are you still in school? If so, do you have a guidance counsellor you can speak to who could speak to your teachers on your behalf to let them know how you are feeling.
There’s lots of self meditation videos on YouTube. I’m making a recommendation that you try listening to some 😊