The meaning of this 痛い


> また首負傷しためっちゃ痛い.

What does this 痛い mean? It sounds like someone is in pain physically? Can it
be emotional?




If this is the full context, this 痛い simply refers to the physical pain the
speaker is feeling in the neck. You don't have to overthink about it for now.

> また首(を)負傷した。めっちゃ痛い。  
>  (Punctuation added for clarity)
>
> (I) injured my neck again. (I'm) terribly in pain.

If you explicitly say 心が痛い, it can refer to a psychological pain, too,
although we usually simply say
[つらい](https://jisho.org/word/%E8%BE%9B%E3%81%84-1) for this sense.

In addition, 痛い on its own has several abstract and slangy meanings:

  1. (situation) "bad", "tough", "inconvenient", "unfortunate"
  2. (personality or phrase) "cringe-worthy", "pathetic", "try-hard"

But I think these are irrelevant in your case.

