left bundle branch block

Hello!  I am a 37 year old female who went to the DR. with trouble sleeping thinking it was anxiety related (because I have recently started my own business which is stressful and I frequently worry about money at night) seeking a sleep aid as this has been going on for months.  I just happened to mention that every now and then it feels like my heart is flip flopping only a time or two each time, but frequently.  They did an EKG and located a Left Bundle Branch Block.  I am not currently on an exercise program due to limited time, but jog once a week with a friend and ran a half-marathon last year.  I have a near 2 year old, am of normal weight and my blood pressure has never been over 110/78 and that was recently (after diagnosis).  Just before diagnosis, it was what it normally is - around 108/68 - hovering around there.  No dizziness or any other problems, except that the cardiologist I went to after my family doctor said I have an ectopic heartbeat.  I will say that for several days prior (I am not proud of this) I was drinking literally only Diet Coke, sometimes 7/day and hadn't actually had a glass of water in days.  Shameful, I know.  They ordered a 30day monitor and a complete stress test.  Blood tests came back normal, but I get my (fasting) cholesterol checked this week.  No history of heart disease except a Grandfather who had an aortic aneurysm after years and years of heavy drinking.  I guess my question is...is caffiene related to such things - particularly the bundle branch block? Is it likely that I have heart diease without any risk factors except my grandfather?  What can be done?  And will I be able to resume an activelifestyle afterwards?  I am very anxious given that I just started a family.  Please help me.