I understand your worries. The same thing happened to me with my first birth (twins - emergency caesarean) and it was horrific; really knocked me sideways both physically and emotionally. My epidural failed and my spinal block failed - I felt the same combination of lack of movement and sensation but feeling pain on cutting that you describe.
It took me four years to pluck up the courage to have another baby. I changed hospital, got consultant care, hired a doula and did everything I could to avoid another caesarean. As it turns out, I ended up with another emergency caesarean as my baby was very ill in utero and in distress. Even in the pandemonium in theatre I still felt a fatalistic dread about the spinal not working. I was just expecting it to go wrong. It didn't - my consultant and theatre team knew my previous birth history and were really reassuring - and I can still remember my astonishment when I realised the spinal had worked and I truly couldn't feel anything. Plus the exhileration when I realised I was going to see my baby being born. I was euphoric.
I'm proof that lightening doesn't always strike twice. We were just really unlucky the first time and the odds are in your favour that things will go to plan this time. What helped me was writing stuff into my birthplan in case it happened again - it was a way of gaining some control and understanding of an event that last time had proved to be beyond my control and comprehension. I included points along the lines of:
Owing to my previous birth (failed epi/spinal - delivery under GA) I would like the following to be put in place should I have to deliver under GA this time:
? photographs to be taken of baby at moment of delivery
? baby to be handed immediately (presumably outside theatre as husbands not permitted to be present during GA delivery) to my husband for skin to skin
? husband to discover sex of baby and inform me
? consultant/anaethetist to offer full debrief of what happened during delivery
There might have been a few extra things but overall this was the gist. So much of my twins' birth was a mystery to me and I really struggled with that. Although I dreaded the thought of another GA delivery I knew that there were no guarantees and noone could promise me with absolute certainty that it wouldn't happen again. This list at least meant that if it did I would have the opportunity to build a picture of what happened and also take comfort from the fact that my baby was in the immediate care of loving family (my husband). These were the things that had been missing the first time - both so important and taken for granted that they will be yours.
I hope this helps. I wish you all the best for your caesarean next week.