what you are feeling is totally normal, I'm in a similar situation myself.
DD (my first) was an em c/s for distress - waters went, no labour started, high BP so syntocinon to induce contractions = distressed baby. I felt a "failure" after DD's birth for a very long time...
Roll forward 2 years & DS was supposed to be a VBAC, but he had other ideas at 40+8 with my BP rising & DS having moved into an oblique lie & a cervix that was not showing the slightest hint of getting ready for labour I reluctantly agreed to an el c/s at 40+10.
DS is definitely my last, so I felt (and still do) sad that I will never experience a VB, although I feel way better about DS's delivery as I know I tried everything I could for a VBAC & it just wasn't meant to be.
Just a few days before DS's first birthday one of my oldest friends had her first baby, 8hr labour, totally natural delivery, no stitches, just the sort of delivery I was supposed to have! And do you know what I was totally jealous when I heard about it! and a little bit sad too....
But what is good is that I'm okay with feeling like that, it's not taking over my life, those feelings last but a few minutes & then life with my gorgeous children carries on.
As Lulu wisely said give yourself permission to feel how you feel, it's okay.
And as for the "friend" who said to me after DS's birth "well I see you took the easy option again, still too posh to push?", well lets say that I don't think he will EVER make another thoughtless comment like that to a woman again!