Trying to re-work a chapter i'm writing at the moment for a story, but it's giving me a hard time. Reconstructed and added to it to where I have about 4 different versions of it with each one making me worry about the character. The main backstory for it is the MC lost his friend and he's morning the loss of her inside a prison/holding cell.

At what point does the story of the character change to where he's being whiny instead of mourning? Anyone have stories they've read where they have seen a character be in mourning or if they are just whiny?

I'm not exactly sure what you mean, but if I understand correctly, you're asking at what point does mourning become whiny, in the context of a narrative?

I think probably the answer is: when you start repeating yourself. Mourning can be difficult to write for this reason, but I think you have to attribute some intelligence to your readers, so that they can assume, even though you've stopped explicitly talking about how much the protagonist feels sad, that his feelings haven't just gone away and moved on to the next thing. Obviously you can continue referring to it occasionally, but commenting that he does every action "miserably" or "with an air of melancholy" is probably gonna make him seem like a manic depressive on a come down.

As to how much "real world" time this takes? I think that depends on his relationship with the deceased. Remember you can always skip over this time with your magic narrator powers...

Sorry if I was unclear, but yes that is what i'm wondering. At what point does the character progress from mourning the loss of someone they cared about to being a whiny little pain in the you know what.

Sadly I am finding that I repeat myself quite a bit where the character hears something or sees something with it reminding of his lost friend. Want to add depth to the character, though not at the expense of him turning into a whiner.