Update:
He's got way worse issues than just swimbladder now. His fins are now heavily frayed and eaten away, andhe appears to have fin rot. On top of that, he has a few white specks on him, so it appears that he also have ich/white spot disease (which I've heard ich and fin rot can go hand in hand sometimes).
I wonder if something lowered his immune system.
UGH, my poor guy. I'm on some fish boards getting some advice on what meds I can treat him with. He looks so pitiful.