You see this man? This is Sam Winchester. He sacrificed himself to save his brother and the whole world. He and his brother stopped the apocalypse. He saved the world and so that everyone else could live in peace, Sam Winchester had to endure 180 years in hell with Lucifer. For 180 years, he was tortured and raped and ripped to shreds by Lucifer himself.
Now, he is out of that cage, but hell is still with him - in him. Lucifer won’t leave him alone. Day after day, he sees Lucifer who delights in reminding Sam of all the horrible things he did to him in that cage. And what does Sam Winchester do? He worries more about Dean (just like Dean worries about him) than about himself. More than anything else, he wants Dean to be okay. He wants to see Dean happy. Sam Winchester doesn’t want anybody to worry about him and he honestly thinks that there are people out there who got it worse. He endured 180 years of torture by Lucifer himself and believes that there are people who got it worse.
And you want to to tell me that Sam Winchester is selfish and doesn’t care about anyone else but himself? You want to tell me that Sam doesn’t love Dean? You seriously want to tell me that you hate Sam Winchester?