Why is Jason finding it difficult to cope in this final section?

Jason is finding it difficult to cope with the idea that the future of the world might rest on his shoulders. He is the son of Jupiter, the king of the gods, and so is looked to as a natural leader. He knows this is his destiny, and the fact that he has to fulfill a great prophecy only makes matters worse for him. He is terrified that he will not live up to expectations, or that he might fail and the world will suffer because of it.