That's the point - focused on yourself and it doesn't happen over night. Your friend wasn't focused on himself but on another! That's the way it should be. But I do know it is very easy to slide into the self pity mode. We must deliberately stop it even if we *think* we have every reason to be there. Because it's lie and believing a lie never ends well.
I wanted to address the part that it is indeed a selfish act. He didn't become selfish that day, he lived with it and dwelt on it in his self-pity mode.
I like your friend, tell him 'thanks' for me. And, I know you, you KNOW God wanted you here! We all have 'Someone' else to focus on - the pain He went through for us - is greater than we can imagine much less experience.
And, yes, it is easier to stand on the outside and he made sure his family/friends where on the outside. One can't go where they aren't allowed. I pray my family/friends never put me in that situation because of pride (you can't know I feel damaged). Did he feel only he needed to be perfect or have a perfect life? And only he should have it? No one is better than another no matter what they have or don't think they have. IMO, if one has Jesus, they have it all. And an eternity more than those who don't have HIM.
Don't because you know nothing about mental illness and the vast number of causes of suicide. Mood disorders, medication, bipolar disorder, personality disorders, schizophphreniform disorder, post traumatic disorder, are just several of the most common causes.......
They all require medical help and in most cases, proper medication.....