So i made my stupid little mod and was really excited to try it out when all the countries that werent in the mod were gone. Now is there anyway i can fix this or is this just a "make a new mod" scenario

Is this the "The Rise Of Telnar" mod? That mod is set to be a Country Overhaul, which means it will remove all countries from the game - and you would be creating new countries to take their place.

If you are only trying to add a new country in place of existing ones (e.g. creating a new Serbia country), but want everything else to be the same, then you'll need to press "Edit Mod" on the mod page, and uncheck the Country Overhaul box.

You may also want to uncheck ideology overhaul too, as that will remove all the base-game ideologies.

AHHHHHHHHHHHHHHHHHHhh thank you so much