Fear

Hi Blop, I am not 100% sure what you mean by ''my voice will break'' but my advices would be:
1. practice back at home, imagine giving presentation in front of all the class, during speaking imagine that they are really there (try to even look into their imaginary eyes). Do it several times until you are not good at it. It might be even good idea to film it, you might notice some strengths and weaknesses you didn't realized before.
2. if you are at university try to join some public speaking courses there are plenty of them and plenty of other students who struggle with it.
3. you can actually modulate your voice, you dont need to speak all the time with same pace, hight, voice intensity. I sometimes speak deeper, sometimes slower and more articulate (for example when I'm occasionally giving lectures and tutorials in my PhD so everybody can hear me loud and clear).

Key is really the practice. Once you successfully do it, it wont come to your mind any more. Good luck!

 

Great advice from @JustinX

I'd like to add that no PMOing will help your voice improve too

Less brain fog > increased clarity of thought > more conviction in your voice

 

@Blop12 Whatever you do, do not imagine them being naked! I tried that once and it made everything way worse. I got all confused and red like a tomato! I don't know who made that advice up but may the doomstick be upon him, god damn!

Like Justin posted above, you need to practice. Practicing and improving will make you more confident of your abilities, because then you will be able to trust them.

 

“According to most studies, people's number one fear is public speaking. Number two is death. Death is number two. Does that sound right? This means to the average person, if you go to a funeral, you're better off in the casket than doing the eulogy.”
― Jerry Seinfeld