Chest Shock like feeling whole body.

Hello Doctor I am 19 years old with severe Anxiety issues regarding health , Multiple specialists told me nothing is wrong with me I am Having a pounding Sensation in Head without pain and the neck stiffness of my neck showed no abnormalities Every 5 seconds when i am lying down why the chest is Pounding hard and I feel shock all over my body with mild chest pain i get this sensation only when I lie down in bed and pounding in head when I sit i won't have any pain This Shock-like feeling from the heart every 5 seconds scares me , i don't get it in college or with people I went to Gp he told my bp is 170 due to panic and My Lipid and Cholesterol levels are very normal I also have Herniated disc in lumbar region which is pressing over nerve in let So I feel that pounding or Shock sensation whole body from chest to whole spine My spine is good I am very scared Please tell me what to and whom to consult