aboonoor:

لاَ يَتَمَنَّيَنَّ أَحَدُكُمُ الْمَوْتَ مِنْ ضُرٍّ أَصَابَهُ، فَإِنْ كَانَ لاَ بُدَّ فَاعِلاً فَلْيَقُلِ اللَّهُمَّ أَحْيِنِي مَا كَانَتِ الْحَيَاةُ خَيْرًا لِي، وَتَوَفَّنِي إِذَا كَانَتِ الْوَفَاةُ خَيْرًا لِي

None of you should wish for death because of a calamity befalling him; but if he has to wish for death, he should say:

“O’ Allaah! Keep me alive as long as life is better for me, and let me die if death is better for me.”

Source: Ṣaḥīḥ al-Bukhārī (5671)
Source: Sunan an-Nasā’ī (1820)
Source: Sunan an-Nasā’ī (1821)
Source: Sunan an-Nasā’ī (1822)
Source: Ṣaḥīḥ Muslim (2680a)
Source: Sunan Ibn Mājah (37/4406)