I'm sorry you're struggling so much, OP. I felt much the same way with one of my children, who was determinedly breech, and had a fear of surgery to go with those feelings that it wasn't a proper birth.
I think a big part of it is sometimes the lack of control. Birth is often portrayed as an empowering experience for women, but a c section just feels like a surgery that's done to you, and you're powerless.
All I can say is that I wish I'd focused on acceptance, and reframing it as positively as possible. The c section itself went pretty smoothly, my baby was perfect, breastfeeding was established quickly, and I recovered fine – but I spent months ruminating on how I hadn't had the birth I wanted and sank into PPD, and all it did was hurt me, for nothing.
16 years later, it feels ridiculous to me that I was so fraught over something that, in hindsight, is so minor – and has a lot of benefits along with any negatives, objectively. It's easier said than done, but I think the best thing to do is to embrace the c section, remind yourself of all the positives over and over, and ask your husband or a theatre nurse to take a lot of photos, if possible, so afterwards if you want, you can see your baby emerging from your body, albeit in an unconventional fashion.