I don't really blame anyone for the apocalypse. Sam didn't know that killing Lilith would begin the apocalypse. Dean didn't want to break that first seal (I mean, come on, of course he was going to say yes sometime. You can't tell me that you could tolerate 1 year of unspeakable torture, let alone 30). I don't really think it's anyone's fault. And, anyways, they stopped it didn't they!
“If Sam finishes those trials, he is going to die.” You know what the worst part about people calling Sam selfish is? THE ONLY REASON IT’S TAKEN HIM THIS LONG TO ADMIT HOW BAD HE FEELS IS BECAUSE HE HATES BEING A BURDEN ON DEAN. WHEN YOU’RE AFRAID OF EXPRESSING YOUR FEELINGS BECAUSE YOU’RE WORRIED ABOUT HOW THEY’LL AFFECT OTHER PEOPLE, YOU ARE NOT SELFISH. Sam has always put other people before himself. WHAT PART OF THAT FITS THE DEFINITION OF ‘SELFISH’? I’M GONNA PUNCH A THING