Trust — Bitachon — בִּטָּחוּן
If worry comes to your heart, take it as a warning from God who loves you.
Examine your deeds and take counsel with those whose advice you seek.
When you have fulfilled His will, trust Him and your serenity will return.
Cheshbon ha-Nefesh (“Accounting of the Soul”) is a step by step approach to improving one's characher traits. It was written by Rabbi Menachem Mendel of Satanov. It was published in 1845 with the encouragement of Rabbi Yisroel Salanter. The book is available from Feldheim Publishers.