Baby bird died.
You did not mean for the innocent creature to die in such an awful manner, but it was kind of your fault. After all, you did put a rock on a sick, helpless bird. Then you thought dirt was a good way to provide nutrition for it. That is strange.
But there is no need to lecture you on your choices. You did your best, and you probably feel terrible for how poorly you performed. It is okay. Everyone makes mistakes. Not many of us accidentally use a rock to keep a tiny, sick animal warm right before we try to serve up some delicious soil, but we all have our own shortcomings.
You tried. That is what matters.