Annnnnd now it's working. I had tried pretty much everything before posting this:
- Turning off and on
- Letting the phone "scan and try to fix errors" (MULTIPLE times)
- take SD card out and plug it back in
- Wait for half an hour at a time
- Many different combinations of the above options.
So as I was making this thread, I deleted a program that was installed on the card so that I could install it on my phone directly. After it downloaded and re-installed, everything was recognized.... I'm not sure if it specifically had to do w/this program, but I did have a lot of links on my start page that I had created with it, and those all went away with it when I deleted the app.
Something to note - the phone DID see how much space and everything was used up in the card, but it wouldn't read any of the files from the card.
I can go ahead and consider this matter closed, but I'll leave the thread in case other people are having these issues.