LH - have faith in yourself and faith in your doctor. You will be fine. I too had major heart issues, along with high blood pressure and high cholesterol. In the Fall of 2015, I almost died while hitting some golf balls at the range. A 911 trip to the hospital that confirmed I was having major atrial afib attacks. After some attempts to control it with meds, one of my cardiologists (a little guy nicknamed Moose - no idea why, but he is also a golf buddy) performed a 4 hour Ablation. Inserting a catheter tube with a camera and a bulb of liquid nitrogen INTO the heart from a groin artery. Moose was very pleased with the procedure - I was and am very pleased to have had it done!
I too will be holding very positive thoughts about this for you and for the success of this procedure.