C-section

So this will be my 3rd c-section. I'm unable to have my children natural due to a small pelvis. I know how this goes. I know the pain and healing that goes into this. I've warned my husband (this is his first child, other 2 are from my 1st marriage) that I'll be needing his help for a good week. But the thought of the surgery makes me sick to my stomach. I know everything will be ok, I know this happens everyday and it's what I have to do to give birth. So why I'm I so terrified?