I was petrified of college and doing class presentations. I voluntarily took a public speaking class my second semester and learned that speaking in front of a larger group can actually be easier than conversing in a smaller group. You can control the cadence and rhythm. It's helpful to have visual stuff for people to look at besides just staring at you, and even better if it's on a screen and the lights get turned down. You will gain confidence with experience, and don't let any blocks get you down (that can be the hard part). Do work daily on your breathing. Meditation focusing on the out-breath has been extremely helpful for me.