There are so many reasons people avoid public speaking, but this is one of the more discouraging messages to tell yourself: "Who would want to listen to me, anyway?"
You should probably have a good reason to speak in public. If you don't have anything to say, you're right: no one will want to listen to you.
But your life experiences are unique and special and your own, and that's the benefit that any audience gets when listening to you. Your story is different.
Say you're asked to give a toast at a friend's wedding. Your stories and experiences with that friend will be like no one else's, and the way you express yourself is 100% you.
Even in everyday speaking situations like leading a meeting, going over a report with your department, sharing workplace tips with a new group of employees at orientation, or introducing yourself at your child's back-to-school night, you have your own twist and spin on things that others deserve to hear.
What makes anyone else more interesting than you? Confidence and self-esteem! If you feel that what you say has no value, you will impose that on your audience and they will agree with you. However, if you believe that what you have to say is just as important as anyone else's story, you become much more interesting!
Reframe the way you see yourself. You have something unique and special to share and a unique and special way of saying it. You have plenty to offer and plenty to say. Now you just have to tell yourself that -- and believe it.
Here are a couple of blog posts on confidence:
Confidence or courage?
Having confidence in your message
Baby steps to fighting fear
Are you prepared to be wrong?