Greetings Celissia, and welcome to the forum.

I want to start with your last statement about attaching the fbx/blend file. I'm not sure if I understood your meaning there. Are you talking about attaching files to your post here in the forum? If so, click on the "Attachments and other options" right below the text box when you're typing your post. It doesn't look like it, but it's clickable. If you're talking about something else, can you explain further, please.
About your main question, can you attach a screenshot of your Painter session, showing your texture sets? Use the same "Attachments and other options" thing.
There are a lot of great people around here, most of them
far more knowledgeable than I, so I'm sure we'll be able to help you get this figured out.
Good luck.