You could have had a migraine variant with just the aura and no headache. Also, the way you were lying could have simply lessened blood flow to the areas causing numbness. If you woke up with these scary symptoms, this could have caused you to panic and the huge rush of adrenaline causes the rapid heart rate/panic attack.
Just because you have a rapid heart rate does not mean you are having a panic attack. Why would you get a panic attack when you just wake up. I can tell yo that I have the numbing at times and the rapid heart rate and I was diagnosed with lyme disease. Do you have any unusual symptoms you passed of as normal or from getting older?
your symptoms are pretty vague, but im sort of going through the same thing myself. weird vague symptoms, rapid pulse, palpitations, worrieness, sense of doom- so i went to the ER a bunch of times and my docs are chalking it up to anxiety. im told it can show itself physically pretty aggressively. i would try to calm down, get control over your own mind and say to yourself its nothing more than anxiety. if you can pinpoint it to some sort of trigger that set it off, that would even help you more. but yeah, iv learned that ERs just want to make sure you are stable and able to keep on living, so if they take your blood, and EKG, and your vitals and it all checks out- they are going to chalk it off to a panic/anxiety attack. you should definitely still follow up with your doctor and make sure he notes all your symptoms and to rule out anything physiologically wrong before declaring it anxiety. this is an awesome site, know that you're not alone. being anxious ***** =/