What would you indicate a “bad parent”

I know people have different meanings…. Just want to know your point of view

Is a tired mom yelling at her child who is fighting their sleep considered a bad mom?

Child 18 month

With a 1 month old

So tired, depressed and I feel bad. Child isn’t sleeping and I yelled at him for fighting me while I rocked him to sleep in my arms. I’m so tired & I know I shouldn’t be yelling at him. I feel like a failure at being a mom..

It’s always at night when I’m so exhausted I find myself yelling at him

What can I do to change this, please help I’m miserable