Thank you for the query.Anxiety
and panic attacks are most probable indeed. Due to unknown factor your brain stimulates the rest of your body what gives mentioned by you symptoms. Very characteristic for this issue is that all tests are negative.
I suggest you to seek for help. Psychiatrist
should be consulted. Sedative medicines and SSRI
(antidepressants) seems to be necessary. Please also start Magnesium
400 mg once a day. Avoid coffee and caffeine drinks.
Hope this will help.