ouch, that is a bad one, especially for a tree frog so sorry, poor Laputa... need to go back and read everything carefully to advise.
you gotta set up hospital set up with covered all 4 sides and top with wet papertowels.
at that point I would do undiluted pedyalyte soaks with added liquid ca, i would suggest to get repashy rescue cal. that stuff is the best. for those not eating powdered crickets all you need to do is to expand water gel crystals with that stuff and use it for crickets.

what was vet's problem with UVB exactly? you need UVB at least 2.0 for a smaller tank.