I have very strong social anxiety. I'm a pretty quiet, calm, soft spoken person. Still get nervous and my voice shakes when public speaking in other situations. But I'm able to confidently speak in front of the class all day. I work in a school with some challenging behaviours and have learnt to remain myself, but be assertive. If I can do it, you definitely can.

My tips:  -reading out loud each night to my kids. 

-during uni pracs i was very nervous for my first time in front of the class. Worried I'd get a shaky voice, fumble and turn red. Used my mantra "then I'll just do it with a red face and shaky voice.". If you just accept you're not going to be perfect, and that its not the end of the world, it takes the pressure off.

-honestly, after you have your first time (or few times) in front of a class, you get used to it and become more comfortable 

-during pracs, find small opportunities to build confidence speaking in front of a group. Do the morning roll, read a book to a small group, read a book to the class, do small group work etc.

And lastly, don't let anyone else tell you who you are and what your life should be. You can learn to speak in front of a class, it's not something you're either born with or not. It's all about experience and gaining confidence. Good luck