Hi Beth. I also agree with sanityThruLight. There must usually be some concern for your safety or others', for IP admissions. Unless, your psychiatrist themself sends you IP for a major medication overhaul.
ERs definitely see people with extreme anxiety. I think many come in fearing a heart attack, or the like. But obviously you are quite attuned to what you are experiencing. You seem to know what your "doom" really is about.
As for them helping, I would think they might offer an idea for a medication adjustment. I'd hope. Or you may well hear a suggestion to go to IOP. You're clearly not a person seeking controlled substances for addiction. Because of that, I do think they'll hear you out a bit. If they wouldn't help, then you'd be experiencing the same lousy lack of care that far too many receive. Ideally, you should be getting sufficient help from your pdoc and tdoc. I'm sorry that you have a bad one...at least your pdoc.
I totally understand your concern about your kitty. It might be good to work out a "plan" for them, if you ever need hospitalization. Crap happens, and often unexpectedly.