اَللَّهُمَّ لَا سَهْلَ إِلَّا مَا جَعَلْتَهُ سَهْلًا وَأَنْتَ تَجْعَلُ الْحَزْنَ إِذَا شِئْتَ سَهْلًا

Allaahumma laa sahlaa illaa maa ja'altahu sahlaa, wa Anta taj'alul-hazna 'idhaa shi'ta sahlaa

O Allah, there is no ease other than what You make easy. If You want You ease sorrow.

Reference: Sahih (Albani). Ibn Hibban: 974