Sorry to hear this! I think you should be able to get your note back!
Hopefully you haven’t gone out of your way to disable the File Recovery plugin. Go to Settings and proceed to the File Recovery plugin.
https://help.obsidian.md/Plugins/File+recovery
Here is a link to an post where someone else experienced the same red dots: A note with few hundred lines of data displays red dots (in edit mode) instead of the actual content and completely blank in 'preview' mode. Cursor placed on any red dot displays "\u0"
Hopefully you are able to get this sorted out. Thanks.