Fear of speaking in public is very normal…even for adults. I am absolutely terrified of speaking in public and I am in my 40s. Yes, even reading at mass terrifies the socks out of me. That does not mean you will be a failure in everything else. You will eventually learn to “get by” even if the fear is still there.
What works for me when I am “forced” to speak in public is I do not look at the people (unless my best friend is in the public in which case I look at her for moral support). I look at the walls, the table, the paintings, etc. This method “unfreezes” me.
Some say to imagine the people naked to take your fear away. This method does not work for me because I start cracking up. No good for public speeches, but it may work for you.
PS. I also feel like I “fail” God constantly through sin, it is a good thing He is so much better and more forgiving than us. Like Jesus says, none of us will “make it” if it weren’t through Him. So yes, we all mess up sometimes, but Jesus is great and is there to save us, our personal failures included.