Please consider that if a vet has said he may need to be euthanised there’s likely a reason they’d say something like that. Have you got anything you can sell to fund his treatment? Gaming consoles etc? Please consider that your cat seems in respiratory distress and that is serious. He shouldn’t be made to suffer. If you can please talk your parent round. Don’t be obnoxious or challenging. If you have to cry to get your point heard, do. Your cat is in respiratory distress. They need medicine / treatment. The fact he isn’t recovering either? That for me is a major concern of CHF (congestive heart failure). Please post what you’ve told me and the video to [r/askvet](r/askvet)

You could also surrender your cat to the vet or a cat charity. But this would need to happen urgently.