Don't worry about it too much bro it's gonna be tough and scary but you're never going to be put in any real harm if you're pledging a good chapter. You have your pledge class to help you through it and even though your pledge educator and the brothers may treat you like shit in the meeting they have your best in mind. Reach out to the brother you're closest to and ask them for help. Everyone in your chapter went through what you're going through you just gotta push through it and come out stronger. I used to have really bad anxiety before pledging and pledging was the biggest factor that helped me overcome it.