It could be selfish, but does that mean it's unacceptable? Where it becomes tricky is where you weigh your needs against those of others. I know of this woman who was admitted to a mental clinic because she could not stop blaming herself over her miscarriage. Eventually she committed suicide because she could not live with the weight she placed upon herself. Sure, she still had people who loved her, and maybe there was nothing she could have done to prevent the miscarriage. Still, there's only an extent to which people can control their emotions. You can call that a lack of strength, but then I ask what kind of expectations you have of a human being?
Even being selfish by default is something I'd pull into question. I've met another girl who had struggled with clinical depression for years on end and didn't see an outcome. She was pretty much diagnosed to never 'get better.' When she made the decision to end her life she explicitly planned her suicide to cause the least possible amount of damage to her surroundings, spent months on how she would be found, how to best convince her parents it wasn't their fault, etc. On her part it was a rational decision, even if it was one that hurt her environment, but it was that or live in despair and be a constant burden on your surroundings because of it. I'm not sure if I'd shelve that under selfish.
I don't think people understand every situation and it's a subject just so far away from them that they sort of generalise it. I'll be the first to agree there's a lot of stupid people doing stupid things and that jumping in front of a car is a total jerk-move given the multitude of alternatives out there, but it's not always so simple.
Protagonist said
As a Christian, I believe that people created for a purpose. By killing yourself, you're usually preventing yourself from fulfilling said purpose, and that's just no good.
I'm going to try really hard not to let my personal feelings on this shine though, so forgive me if I do, but I want to ask you if you believe god created you the way you are, but upholds the same bar to get into heaven regardless of the trials he puts you through, is it fair to judge persons with different living conditions or health concerns than you?