For the past 4 years I have been experiencing unusual symptoms. I have a shocking feeling in my head along with light headedness, cold feelings all over body. Buzzing/ tingling feeling throughout body and facial numbness. Sometimes I feel like I'm having trouble breathing, though I am not. I feel like my heart is racing but it is normal. Mostly, these problems start at night and make it difficult to sleep as I begin to think I'm dying and start feeling nervous/ anxious. I have seen multiple doctors and have had multiple test with no outcome.