He had turned into an embittered, hardened adult.

他已经变成了一个愤世嫉俗、冷酷无情的成年人。

Gerald turned sour and embittered when he felt people were not dealing honestly with him.

当杰拉尔德感到人们没有真诚待他时，就变得乖张易怒，怨恨不平。