What am I supposed to do (from Supernatural)

You know, when we were little, you couldn't have been more than five, you'd just started asking questions. [bad word] we didn't have a mom; why do we always have to move around; where'd Dad go.. when he'd take off for days at a time. I remember I begged you, quit askin' Sammy, man, you don't wanna know. I just wanted you to be a kid. Just for a little while longer. I always tried to protect you, keep you safe. Dad didn't even have to tell me. This was always my responsibility, you know. It's like, I had one job. I had one job. And I screwed it up. I blew it. And for that I'm sorry. I guess that's what I do. I let down the people I love. I let Dad down, and now I guess I'm just supposed to let you down too. How can I? How am I supposed to live with that? What am I supposed to do? Sammy... God... What am I supposed to do? [screams] What am I supposed to do?