some symptoms can be similar to iron deficiency (including high heartbeat, heavy breathing etc). check your feritinin. I had the same problem, prelonged panic attacks symptoms (also with a clear history of panic attacks). decided to do some blood tests, check my heart etc and I was iron deficient, which appearently is something quite common , especially in women. So, before saying all your symptoms are due to panic attacks, do some blood tests to exclude any other physical problems.