我的难过说不出来的英文是怎么翻译

六楼的表达不错

I'm short of words in expressing my sorrow (sadness).

这样应该比较符合英语习惯，或者像六楼的朋友那样

I cannot express my sorrow (sadness) through words.

我的难过说不出来
My sad feeling is hard to tell.

It is my sorrow/sadness that is hard to express with words.(强调句句式，it is和that可以去掉）

my sadness which cannot be spoken out

I can't say my sadness.