To get yourself away from disappointment, sorrow, hardships and misfortune, after every namaaz you should keep your right hand at the place of sajdah and then extend it from your left cheek along your forehead till the right cheek. You should repeat it thrice and each time you should recite the following du'aa:
“Bismillahir Rahmaanir Raheem.”
In the name of Allah, the Beneficent, the Merciful.
Transliteration : - “Bismillaahil lazee laa ilaaha illa Howa Aalemul Ghaibe wash shahaadate Howar Rahmaanur Raheem. Allaahumma azhib annil hamma wal hazana wal fetana kullaha maa zahara minhaa wa maa batana.”
Translation : - In the name of Allaah other than Whom there is no God. He knows what is hidden and what is apparent. He is the most Beneficent and Merciful. O' Allaah remove from us all our sorrows and grief and save us from all the evils surrounding us whether apparent or hidden.