How can I control having a nervous voice when I speak in public?!

Try not to worry too much, it happens to the best of us. The reason you're probably more nervous now than you were before is most probably due to the fact that you're now more aware and self conscious however there's nothing to worry about.

When presenting make sure you have practiced, eye contact is essential to engage with the audience nobody likes someone starring blankly at a piece of paper. My advice to you is, try not to worry because at the end of the day, you're not the only one who's going to have to present, others will too and they're just as likely to be as scared as you are. If you feel yourself going to stutter or jumble your words up then pause, take a breather nobody is going to put you down for it, taking a breather will allow you to focus and concentrate rather than rushing ahead and speaking really fast. Take your time and don't rush.

Experience

i have the same problem, i cant talk in front of large groups of people, sometimes it helps if you just stare at the back wall and try your best to pretend your by yourself.

Speaches

practice, practice and practice. but its not always easy. this is common. try looking at the wall while presenting. or people's collar rather than straight into the eyes.