Very Scared after Atrial Fibrillation

I was just released from the hospital after suffering Atrial Fibrillation.  I was given DiltiazenCD 120mg and Flecainide 50mg X 2 to be taken every day, with an aspirin.  I was kept one day afterward for monitoring, and then released. I was told I could resume normal activity. My afib lasted roughly twelve hours. I attained cardioversion 45 minutes after being treated with the Flecainide.

I have read much about the dangers involved with taking Flecainide, and especially of taking it with Diltiazen.  I am very scared.  Are these drugs commonly administered in this way?  I have a follow up visit in one week with the hospital cardiologist.  However I am worried about taking these medications.  I was told I will have to take them for the rest of my life.  I am a 61 year old male, 145lbs.  Have had no prior history of Afib, but have had PVC's for most of my life as well as panic attacks.