I got an ancient Chinese quote from Mengzi that I like a lot and often recite to myself whenever I face stress or hardship.

天將降大任於是人也，必先苦其心志，勞其筋骨，餓其體膚，空乏其身，行拂亂其所爲。

It roughly translates to

When Heaven is about to confer a great responsibility on a man, it will first test his will with hardship, exhaust his muscles and bones with toil, starve his body and skin, deplete his resources, and frustrate his efforts.