I understand the roller coaster I'm on it too and I have anxiety like yourself so it doesn't help. Hope he does ok.So-so. He's still eating and drinking some, and using the litterbox without sign of major GI distress, but also still quite reclusive. He let my mom pull him out for some petting and snuggles, which he purred for, though he didn't get very "into" it or stay out once he was let go.
He's out of NSAIDs now, so we'll see how he's feeling off of his kitty advil. I'm hoping it wasn't just that making him feel better. =/ Thank you for checking in! I just wish we knew for sure what it was. It's such a rollercoaster wondering if it's FIP or just a big out of control.