Do I need to change…something…so I can keep the double space format when I post on Facebook?
By the way, I just realized that I didn’t answer the Facebook part of your question…FB questions are not really welcome here, but I’ll answer it indirectly: Web sites do different things according to their programming when users input data. For example, this website will do the following if you attempt to add extra vertical whitespacing in a posting:
Imgur
I’m not saying that there aren’t ways around this for the FB “problem” you are experiencing, but I’m not going further with that here, mainly because I don’t care–sorry. My main point is that you might do something in Notepad++ that appears to solve a problem when viewed with Notepad++, but text copy-and-pasted is at the mercy of how the destination wants to process it.