My first ever panic attack?

by Rachael
(Leicester)

I'm 37, married with 3 kids and my doctor thinks I've had a panic attack. I'm not entirely convinced though. I am going through a stressful time at the moment but nothing worse than I've previously experienced and this morning for no apparent reason I got sudden intense yet intermittent pains in my left shoulder between my spine and shoulder blade. I was not feeling panicky or anxious and had not made any sudden movements or recently done anything strenuous that might have caused the pain. I did become panicky when the pain started because it was hurting to breathe and I couldn't understand what was happening and why it was happening. I did for a few moments actially think i was having a heart attack or going to die the pain was that bad. There were short pauses in the pain when I was briefly able to get my breath back before the wave of pain started again which felt like someone was slowly pushing a knife into my back. This lasted for probably half an hour to 45 mins but it seemed like hours.
I went to see the GP who believes it could be either a panic attack or muscular/skeletal tension due to stress/anxiety.
I have spent the day in bed and although the pain is not as bad I have still got a dull ache in my shoulder and chest on the left hand side and have decent yet restricted movement due to the pain.
I'm really just wondering if anybody else had experienced a panic attack similar to this?
My experience sounds a bit different to the many stories I have read about on here.
Thanks anyone for any feedback.