Harsh world.
Some things you can fix, and walk away, and get on with your life.
Other things will turn your life upside down. You can't fix everything, and there is always another.
Your father could have let you take the dumped kittens, and you could have then dumped the same kittens at the local shelter, which likely already has too many kittens.
I've volunteered at two animal shelters. The reality of this constant inflow of lives...it is sobering.
We all have to pick our battles.
It's a jungle out there.