I have social anxiety disorder. When I was in college there was a mandatory
speech class. I think it was debates. There was no way I was going to be able
to do it. I asked if I could take an elective speech class. They agreed to let me.
I was very nervous. I had to make a speech about different subjects. Being very interested in each subject I chose helped. Calming breaths before getting
up in front of the room is good. There used to be speaking group years ago.
Called Toastmasters. To help improve You improve your public speaking.
See if it's still around. Good luck.

First this is an important skill that could help you later in life, so confront your fears now, in a venue where people are there to help. Put in the time, spend 100 hours, knowing your subject matter, writing down your speech, practicing it 40-50 times. Then given your familarity with the subject matter and practice, you will feel comfortable up there.

Don't put unreasonable expectations on yourself, just have I done as good a job as I can.

Stand in front of mirror. Practice looking confident until you can feel it naturally with your eyes closed.

Do the speech in front of the mirror, checking your appearance to keep your face calm and active, until you can feel it naturally with your eyes closed.

That way, you can feel the confidence in yourself when you are in front of an audience.

Best wishes as you gain the knowledge, skills, and ability to be confident doing this!

I have had problems with this my whole college career. Honestly, I have never really found a good way to fully manage my anxiety during presentations, but I have came up with some coping methods. I like to start of by mentally preparing by reassuring myself that this is literally nothing but a thing. I am not the only person in the class presenting, so I am probably not the only person experiencing heavy anxiety. Also, it is important to remember people are a lot more supportive than you think.

Toastmasters is definitely still around and the perfect solution for your public speaking anxiety. I have been a member for over 20 years...Its a very supportive organization and you will love it. Google Toastmasters International to get to their website...you will be able to put in your zip code to find a club near you. With the Pandemic all meetings are now on zoom.