If we can accept those things we cannot change, our choices will be different, yet wiser. Which will reduce a lot of anxiety and pain, and will make us happier.
In everything, get understanding.
Proverbs 3:13 (KJV) – happy is the man that findeth wisdom, and the man that getteth understanding.
Proverbs 4:7 (KJV) – wisdom is the principal thing: therefore get wisdom: and with all thy getting get understanding.