This du‘a ‘Ya Hayyu Ya Qayyum…’ was narrated in a sahih hadith from Anas ibn Malik. Imam Al-Mundhiri and Shaykh al-Albani said: its isnad is hasan. For more about the meaning of this du’a, please see the detailed answer.

It is not permissible to single out certain verses of the Quran to recite for specific purposes, unless there is specific Shar`i evidence to that effect. Therefore, there is no specific surah to recite when in difficulty.