Have Mental Health Questions? Ask a Psychiatrist Online
Sorry to hear that you are struggling right now. I imagine you told the office that even though it has been 8 years, you are not a new patient? If he can't see you then I would find another doctor that can see you soon. I may also explore getting into therapy so you can explore why the panic attacks are coming back so you can get the support in addition to medication if needed.
You may also think of calling your current general practitioner so you can be seen sooner and they can also refer you to a Psychiatrist.