Prophet (SAW)'s Prayers When tired of life

Due to difficulty death is sought but one should never pray for death
instead pray this:
اللَّهُمَّ أَحْيِنِي مَا كَانَتِ الْحَيَاةُ خَيْرٌ لِي وَتَوَفَّنِي
إِذَا كَانَتِ الْوَفَاةُ خَيْرَاً لِي
"O Allah keep me alive as long as is good for me and when death is
betterfor me lift me".
(Mishkat)