Hi sallybobs and

to DF!
I'm not a doctor either, I'm an RN, but I'm inclined to agree with you, as to the likelihood of a misdiagnosis.
Do you FEEL panicky during these attacks?
Do you have a feeling of doom, fear that you are having a heart attack or dying...?
If you don't have the above, it sounds like you should be going to someone who can do an EEG, like a neurologist, because these symtoms sound more epileptiform, than due to panic disorder. Epilepsy takes so many forms from very full-blown attacks, to partial seizures, to mild "absences". The whole-body muscle contractions could be a symptom of some form of mild epilepsy, since you don't lose consciousness and retain your awareness. I don't know if GPs diagnose epilepsy, but you are well within your right to get a second opinion.
I've experienced both panic attacks and RLS (Restless Legs Syndrome) - oh, the joys of the side-effects of various medications!!!! - but neither of these quite fit what you seem to be describing.
Of course none of us can diagnose anything online, but I agree with those who say get another opinion, or if you can, a referral to a neurologist.
And good luck!