This indicates severe airway obstruction, typical of pneumonia. Unfortunately, this will require injectable antibiotics that you can only get from a vet. Usually the course involves Baytril (enrofloxacin) or amikacin over a period of days. A good vet will usually give you a syringe with instructions as to dosage, that you can administer at home. Nonetheless, treatment will not be cheap - the vets have to make a living. Your primary injection sites are in the loose skin between the front leg and the shell, alternating sides. Try this to comfirm pneumonia: force the turtle to withdraw its head rapidly into its shell and listen closely to the breath sounds. If there is a "crackling" noise (and if there is nasal discharge), it is probably pneumonia. Unless the animal is completely debilitated and unresponsive, turtles usually repond quickly to treatment. DO NOT believe anyone that suggests "home remedies" for this condition. If your vet is in doubt as to drugs or dosage, I will be happy to provide them. Just post here. DO NOT accept any drugs from the "penicillin family" of antibiotics. Most are useless.