hello anxiety can give you many problems and what you are experiencing is not uncommon..you have done all the right things and medically your fine and apart from excessivly worrying you are sending signals from your brain to assume that your problems are more serious..
I would try and find relaxation classes near you or better still buy a dvd and learn techniques to help you breathe through an anxiety attack as this can control palpitations you may experience..
once you learn to control you symptoms you are in control of your body instead of your body controlling you.
also check your leaflets inside the boxes of any medications you are on as side affects can increase symptoms and cause some of your problems.
vertigo is not nice as i suffer from that and have the same symptoms you experience and anxiety is just as bad.
my first attack i thought i was having a heart attack with all the different symptoms it caused..
I use kalms which is herbal and dosen,t make you drowsy and if you feel content then your symptoms don,t control you.
im only a supporter and not medical but its how i have coped for years so i hope some of the information helps you..watch for other replies.
good luck.