Well it seems a little oxymoronish to Kill and be Kind at the same time.but being kind is the right thing to do, maybe instead of killing them they will learn to be kind also, or just be kind in return. The Golden Rule if you will.
Think positive, be positive, and be you in a positive way. Stop worrying it will stop you from thinking happy thoughts. Its time we worry only about how to stop worrying and to just be happy. just be happy