Do sit with that feeling of not being ready, and gently question it: not ready for what?
I hope none of this discourages you from telling the stories you want to tell. They are valid, valuable stories about things that really matter, and there is an audience out there for them.
Asking beta readers to start reading, finish reading, and talk to you about what they read doesn't seem like a lot, but it can feel pretty daunting from the other side.
Critiques should not make you question the value of your work, or the value of yourself.