Hi Nikool, With my experience with this it's a bit like which came first? The chicken or the egg. Laura is right it is so easy to pass off ailments with the diagnosis that you are having anxiety, but when you wake up in the night or are awake in the middle of the day and all of a sudden you feel like you can't breathe, swallow and something is strangling you, it's like hello I think you are going to have panic issues. I actually worry about letting the GP know this is causing me panic because of that reason. They just seem to zoom straight into the oh you are having anxiety. I see.
My adivce to you would be, get the tests done. As far as the panic issues go, it is natural to feel like this when you have these sort of symptoms happening, I would get to see someone who can teach you some kind of relaxation.
Take care, hope you are feeling better soon