I have a small gap between mine, and like you was worried about the toll it would take on my body, and how I'd actually manage it all! I didn't have a C-section with either, but I did have a tough birth with my first, who was also extremely colicky (in hindsight I suspect undiagnosed silent reflux), and screamed at us for 6 months solid. I then found pregnancy very tough - I was extremely sick, and I've never had childcare, so looking after a baby at the same time was, frankly, exhausting and emotional! HOWEVER, babe number 2 was a totally different experience. Easy lovely birth and so laidback! My physical recovery was speedy (except for an issue with low iron due to blood loss - moral of the story, always push for a transfusion!), and my newborn was happy in the sling so I could do more with my toddler. Genuinely, it was so much easier than I had anticipated. Obviously I was lucky with an easy birth and easy babe and I appreciate this isn't guaranteed (and, for balance, he didn't sleep longer than 90 minutes until we got a sleep consultant 13 months in!!), but the fact I was more relaxed, distracted and confident second time around definitely helped.
Top tips: use a sling. Have a bouncer in every floor or in every key room in your house. Have a bag of nappies, wipes, muslins, snacks and spare clothes in your change bag, in your house and in your car. Get out and about, you'll feel better. LOOK AFTER YOURSELF. Shower/bath when you can and eat well. Be brave and chat to other mamas of 2 at playgroups etc., they're the only ones who'll understand and tolerate the joyous chaos, and they'll keep you sane.
Best of luck to you. My second baby is funnily enough now 16 months old, and I'd absolutely love another!! 