You definitely need to go back to your doctor, your medication isn't doing the job for you.
But you also need to get into counseling to learn how not, to obcess over your health. If it's one thing I've learned in all my years, worry helps nothing, nor does it change anything, what will be, will be. You need to enjoy each day, none of us know what our futures hold. So instead of spending your life worrying about what "might" happen, spend it enjoying all that is.