It was reported from ‘Abd-Allaah ibn Mas’ood that the Prophet (peace and blessings of Allaah be upon him) said:
person suffers any anxiety or grief, and says:
Allahumma inee ‘abduka, ibnu ‘abdeka, ibnu amateka, naa ‘seyatee beyadika. Maa dhin feyya ‘hukmuka. ‘Ad lun feyya qa dhaa uka es aluka bekullis min huwalaka sammayta bi hi naf saka ae enzaltahu fee ketaa bika. Aw ‘alamtahu a ‘hadan min khalqika a wis ta’ thar ta behi fee ‘il mil ghaybe ‘an da ka en taj ‘alal qur’aaaaan na rabee’a qalbee, wa nuu ra ‘sadree wa jalaa a ‘husnee wathahaa ba hamee.
O Allaah, I am Your slave, son of Your slave, son of Your female slave, my forelock is in Your hand, Your command over me is forever executed and Your decree over me is just. I ask You by every Name belonging to You which You named Yourself with, or revealed in Your Book, or You taught to any of Your creation, or You have preserved in the knowledge of the unseen with You, that You make the Qur’aan the life of my heart and the light of my breast, and a departure for my sorrow and a release for my anxiety.
- but Allaah will take away his sorrow and grief, and give him in their stead joy.” (Ahmad 1/391 and Al-Albaanee declared it sahih.)
Reference : http://alqamardesigns.wordpress.com/2008/02/02/duaa-to-ease-anxiety/