Reading the first chapter makes me remember tate no yuusha.
Regarding suicidal motivation, I personally think its not far off from real life as much, as it depends on mental health of mc at that time as well as mc's tolerance level to his current situation, irrationality and illogical actions are usually traits of mental stress too, hence it doesn't have to be a big motivation. But this is a manga and author didnt wrote the motivation behind suicide attempt as strongly.