I shouldn't have done that.
Maybe. But you did.
Why feel shame?
Like a toddler learning to walk, you fall down. You try again. Fall down again. Make a correction, and so on.
During this process of learning, it doesn't help much (not at all, actually) to feel shame. The toddler doesn't know any better — and neither do you — otherwise you would very likely choose differently.
The helpful question to ask is: Is this behavior conducive to my practice? You decide.
Every action has its proper place and application. Nothing is absolutely good or bad.
The question is: Does it help or hinder your evolution?