i think the "that which does not kill you makes you stronger" quote is pretty harsh...
Yes, that quote is a wry commentary on life, intentionally so. "Shit happens!" is along the same vein. Life's bottom line: whatever stress you don't master will keep on presenting itself to you; the longer you resist learning how to cope, the longer you will suffer. Pain is inevitable, suffering is optional.
i think physical health and strength do wonders to lend resiliency to the emotional and spiritual body.
It goes the other way, too: if you learn to master your emotional and spiritual bodies, your health will improve.
Tribe_, Jessica and I are giving you opposite advice, but there is no "who is right and who is wrong" here. I hope you can use both perspectives to find your own, and realize that Jessica doesn't always "quit" and I don't always "stay" in stressful situations. And as Jessica said, the in-your-own-head conversation that you develop as you go through this situation is very important, so do pay attention to what you are thinking, to what you really want.
For example, what if you realize that you don't want to continue with hockey? It's not that easy to think that now, because those other voices in your head will argue that you have always loved hockey. You might worry about what others will think if you decide that this level of hockey playing is not fun. Concerns like that can cloud your vision, but don't worry because so many people change their mind. You have a right to change yours, too. You might even get stuck because you don't know what you really want to do, but it is not necessary to know what you want to do next before you quit going in the wrong direction.