Hello and welcome to HealingWell. I have no personal experience with open heart surgery other than my elderly sister had open heart surgery for a much different reason.
I can understand your anxiety and fears of facing this type of surgery. An important step in dealing with surgical anxiety is to become as well informed as possible regarding the surgical treatment. Having a complete understanding of the procedure, why it is indicated, and how it is performed can relieve a great deal of worry. An understanding of anesthesia and the low risks of having anesthesia may also help with concerns about surgery.
It is essential that any patient ask questions and find answers until the decision to have the surgery and the choice of surgeon is fully understood.
I wish I had more to offer you other than my support. We have a great anxiety forum here in HealingWell so do feel comfortable posting in the anxiety forum also. You will find me in that forum too.
Sending you many prayers and good wishes and please do keep talking with us. Hopefully a member with experience re this procedure will be along to talk with you.