I don’t think of all the misery, but of the beauty that still remains.” — Anne Frank

 A well-known Anne Frank quote similar to what you wrote is:

“I don’t think of all the misery, but of the beauty that still remains.” — Anne Frank 

In context, she goes on:

“Go outside, to the fields, enjoy nature and the sunshine … think of all the beauty that’s still left in and around you and be happy.” 

If you like, I can pull together a few of her most hopeful / beautiful quotes — do you want me to?