First and foremost, we would like to stress the fact that a Muslim always resorts to Allah and takes refuge in Him from Satan and his whispers. So, whenever evil thoughts, doubts, or whisperings occur to a person, he/she should come closer to Allah, seek His help and refuge by making du`aa’ (Arabic for: supplication), dhikr (Arabic for: remembrance of Allah) and reciting the Qur’an as well as accompanying righteous people and engaging oneself in good and beneficial deeds. Du’a is recommended in all times whether in prosperity or adversity.
Regarding a specific du’a to facilitate marriage, there is nothing in the books of the traditions of the Prophet ( peace and blessing be upon him) that specify a certain Du’a. There is no authentic Hadith that refers to this issue. However, one can use any formula to ask Allah the Almighty. One may observe what is called the prayer for a request to be answered or (salat qada’ al-Hajah) in which one can pray and ask Allah for what he or she wants. There are some conditions for the du’aa to be answered such as: refraining from asking Allah for something that He prohibited and that he acquires his livelihood through legal ways. All his provisions (food, cloth, etc) must come form a way that is pleasant to Allah the Almighty. The Qur’an is full of supplication that one can use and add his or her own request to them.