There's actually a lot of reasons behind this - first, your hips have changed (therefore, your midsection). As you prepare for childbirth - even before labour - your hips start widening. Sometimes they go back to normal, usually they don't right away and sometimes they just don't go right back to normal. Unfortunately, this is beyond your control.
Your breasts are the same way - they're growing whether you like it or not during pregnancy and even if you didn't breastfeed (I didn't), they can go up a size or change shape a bit thus changing your clothing.
There's also your ab muscles and the dreaded Diastasis Recti. Think of your abs like an 8 pack of coke with that plastic bit holding them together. Now pull on both sides and back and forth. Eventually, it'll stretch. When you stop pulling, it might go back to almost normal but it's still flimsier, weaker and sometimes torn - there's your abdominal muscles. With a c-section, you have an added separation that needs to be addressed - same idea, it might go back to normal, it might not. Unfortunately, this is another thing that may not be fixable without surgery to go back to 'before baby' looks.
Your body needs time to heal and go back to normal. Don't forget that if you gained fat but lost muscle, you're going to look different too. There's always that rare person who bounces back with ease - but most people don't. We have a bit of an unnatural view on what we 'should' look like after pregnancy and let's be honest, we're pretty tough on ourselves to be super-moms. We need to be the perfect mom, wife plus awesome looking to boot immediately.
The bare bones is you may not go back to your previous size and that's okay. It may take a couple of years for you to get back to your previous size - that's okay too. Right now, focus on health, wellness, baby and settling into a new exercise routine as baby constantly changes (constantly!!!). My youngest is 7 months, my oldest will be 2 in January - 2 c-sections. I've found personally, dieting before 6 months was impossible. I was exhausted, my hormones were a mess and I had NO idea if I wanted another baby (I 100% don't and we're done). 2 weeks ago, I was able to join a gym, go faithfully, start eating a LOT healthier and get a good nights sleep again - 14lbs gone.
Good luck but it took 9 months for your body to get this way - give yourself 18 months to see how far you get with diet and exercise
