I'm not a pro, but I'd suggest finding a better vet cause if this is continuos fast breathing it's not just being nervous. Could you get a tape? Cause I'm not completely sure what you mean.. Like, is it audible or what?
Darcy has had very fast breathing ever since I bought him 8 months ago. When normal birds breathing escalates to fast breathing he escalates to open mouthed breathing. He's going to the vet on monday. I let you know what the vet tells me and maybe that will help you