MAY??? This is February....Maybe I'm pushy, but I'd be on the phone every week "pleasantly" (and I mean very nicely because it might take you weeks!!) asking if they have had a cancellation, that my symptoms are very bad, NOT any better. Then I would call again the next Monday...and the next! If they say they will call you, that you don't have to call, nicely say that you don't mind, you are feeling so terrible, that it's not a problem to call. And DO call
And I am saying this because I also have chest pain/palpitations. It is scary as hell!! And I did call for two weeks and finally there was a cancellation or I would have had to wait two months. I believe in the "squeaky wheel" theory of getting appointments.
Good luck....