When you say 'absolutely terrified', only you know how you feel.
There is a normal range of anxiety and fear about birth, and then there is a point at which it is utterly disabling, dominates your life and is a serious problem. i.e it becomes a phobia.
A good comparison is mood and depression. Everyone can feel down and miserable, and seriously unhappy. For a few people that crosses the line into something more serious, which is depression.
A phobia about childbirth is called tokophobia. It can be secondary (after someone has experienced a very traumatic vaginal birth), or primary (someone has never given birth but has a phobia). Women with this phobia will often try desperately hard not to get pregnant, and may terminate a pregnancy rather than give birth. Even if they want a family.
I have primary tokophobia and had a planned CS last year for my first DC. It was a great birth, and I am very grateful to the midwives, consultants and perinatal psychiatrists who were instrumental in organising it for me.
People with primary tokophobia sometimes, but not always, have a history of sexual abuse, assault and depression. Some women find counselling useful. It is not a magic wand, but is successful in some cases, allowing women to attempt a vaginal birth instead of a CS.
Women can have a lot of anxiety about birth for all sorts of different reasons. I think it's important to identify what your fear is, as specifically as you can. If it's pain, there are ways of trying to deal with that, from epidural to other, less medical and invasive techniques. A doula is a solution for some people, to provide emotional and practical support. Some people embrace homebirth. All I'm saying is, identifying whatever it is you find terrifying will help you try and plan the birth that is best for you, whatever that turns out to be.
A CS is of course major surgery, although planned CS's tend to be much easier experiences than emergency caesarians. Most women do not want a CS, as for them a VB is preferable. For me, the negatives of a VB in terms of psychological effect were so strong, the balance tipped, and a CS was best for me. My recovery was excellent, my DC was exclusively breast fed, and I spent a short 2 days in hospital before coming home.
I say this NOT in any way to sway your decision. You will note that as someone who has had a very positive CS experience, I am not browbeating you with negative stories of VB, for example. There are risks with every kind of birth. Different risks carry different values for different people, and there are unfortunately no crystal balls/guarantees for how things will go.
Only you know how you feel. I wanted to post because I think that tokophobia is genuinely hard for lots of women to understand (I am not for a second saying that you are tokophobic, btw - no one can diagnose anyone else on a message board!). I have only responded because you used the word 'terrified', and there's a question in my mind was to whether you are 'crossing the line' from a reasonable anxiety to a disabling fear.
Whatever you decide, I wish you all the best.