she's suffering と she's hurting と she's going through stuff はどう違いますか？説明が難しい場合は、例文を教えて下さい。

She’s suffering → She is very upset, uncomfortable, and possibly even in physical pain. One might be “suffering” if a close family member died unexpectedly, or if they have a serious illness/injury.

She’s hurting → This is rarely used to mean that the person is in physical pain, but much more commonly it refers to mental sadness. Someone is described as “hurting” when they leave a long-term relationship or they get into a serious argument.

She’s going through stuff → In my experience, teenage girls use this phrase when they are talking about a girl who was rejected or broke up with a boyfriend. Teenage boys don’t say this often. Older people don’t say this often either, but when they do they tend to mean it a little more seriously. Typically the phrase is used to convey the same level of severity as “she’s hurting”, so they might be talking about someone who got a divorce, lost a friend, or is fighting an illness. Most importantly, the connotation (“hidden meaning”) when someone says this phrase is that they don’t want to tell you any more information about the “stuff” that the person is going through.