Kindness meaning is determined by you. Kindness is how you choose to show it. Kindness can be empathy, acceptance, kind gestures, thoughtfulness, the possibilities are entirely up to you.
We usually consider being kind towards others. Have we forgot the one person that needs kindness to be able to show kindness?
Imagine if self care was a natural thing these days, the self help section would disappear. There would be a large area in the book store to put more sofas.
Being kind to yourself no matter how miserable you feel should be easy. Give yourself a break once in awhile, learn from your misery and be gentle when you feel down.