I wish I had more to tell you- I never had a C, but with my 2nd birth I also had a lot of anxiety about leaving my older daughter home. She had never spent a single night away from me (and we co-slept, so she had spent every single night in my bed) and she had never really been watched by anyone else even during the day. That for me was the worst part- thinking about leaving her, especially to go do something that would completely change her world. I think what helped was just talking to other people who had a second one, and just realizing that in the grand scheme of things, this would be just a short time away, just a blip on her radar screen. That and the fact that I was going to have no other choice!!
I prepared my daughter a lot- she came with me to the birth center for all my prenatal appt's so that she would know that's where I would be when the time came. Every time we went I explained to her again that Mommy and Daddy would come by ourselves to have the new baby and that she would be staying at home, probably with Gramma or with our neighbors. On the day of the birth, we ended up leaving right before her bedtime, and she waved to us from the porch with my mother-in-law. I couldn;t believe how easily she said goodbye. My mother-in-law slept with her that night and said she woke up a few times, but her gramma told her, "Mommy is at the birth center having the baby" She was fine with it, and that happened the second night I spent away too.
I guess what i'm saying is that I was amazed at how my daughter coped, even though, like I said, she had been with me every single night of her life. I know that having a C section is much more intense with more recovery time, so that might be difficult. I think the best thing I did was just to prepare my daughter well, and just do my best to get over my anxiety by frankly just realizing that I had no choice but to be away and give birth to the baby!
Sorry if this doesn' help you at all, I just thought I'd pass along my own experience. i wish you the BEST of luck.