all i can say is one soak this animal for 15mins three times daily starting right now to maintain hydration. 2, get it back down to the vet, get him to excavate a fecal sample and check for parasites. if possibly research blood taking and get a blood sample. take a smear and do a white blood cell count, all so look for any abnormalities. continue maintaince care, heat and hydration if needed tube feeding with hill prescription diet a/d. find out what antibiotic he gave it and what dose. you also want to find out what this lump is, the vet can decided how he wants to check that, whether they want to aspirate it or get it xrayed. unfortunatley he doesnt sound very well. but that does not mean its not saveable. well the above is waht i would do, there is soem very good exotic veterinary book that im sure he could get a hold of, if not get him to contact a reptile vet via phone.
cheers
H.