I sometimes get that feeling regarding my limbs as well. It is only when my usual anxiety turns to panic. I just thought I should mention that as it sounded familiar.
Just some more thoughts...
You mention headaches as well. Have you ever had any tests for seizures or checked for migraine?
If I were you I'd ask over on the
Epilepsy Forum
includes seizure disorders
You could also check out
Headache Forum
[including migraine]
There's a Forum Search Feature at the top of each page. You could maybe check that using specific keywords.
http://neurotalk.psychcentral.com/search.php
I hope you find some answers.