I had a similar experience to you with DD1, 71 hour labour, awful back pain, failure to progress then emergency section. I'd been looking forward to a calm, drug-free birth, couldn't have gone more differently than expected!
To make things worse, she struggled to latch on and ripped my nipples to shreds within days.
I was so miserable and felt like an utter failure. I really thought I'd be "good" at birthing and feeding babies, then I wasn't! And everyone around me was! (Obviously this is nonsense, but it's honestly how I felt.)
However, by the time she was probably just over 1, I really felt like I was at peace with it all.
A few things helped me come to that point. I did a birth reflection at the hospital when she was 9 months old which helped me to understand what had happened, and how a CS was probably always inevitable, despite any choices I did or didn't make.
Also, we sorted out the feeding issues and I ended up breastfeeding until she was 18 months old.
And time is a great healer too, as you realise that the birth is just the tiniest, most insignificant part of motherhood.
If it helps, I have since gone on to have a wonderful VBAC, but I entered the hospital with DD2 on her way knowing that it could end in another CS, and feeling absolutely fine about that.
Enjoy your beautiful baby. 