Anas ibn Maalik said: "Whenever something distressed him, the Prophet (Peace & Blessings of Allaah be upon Him) used to say: ‘O Ever-Living, O Self-Sustaining, by Your mercy I seek Your help." (Reported by al-Tirmidhi, no. 3446). You must recite these du‘aa’s, may Allaah benefit you thereby and replace your sorrow with joy. May Allaah bless our Prophet Muhammad.