Congratulations on the birth of your baby!
My BEST advice is to do as little as possible for the first 2-3 weeks. Do not clean your house, cook, go up and down stairs a lot. But do walk a tiny bit so you don't get a blood clot or deep vein thrombosis. I recovered VERY well from my c-section, and my recovery is directly linked to having people around me doing everything. It sucked. I made the mistake at 12 days post-partum in carrying a load of laundry up 2 flights of stairs. I was in awful pain that night. Lesson learned. Don't do anything for the first few weeks! Only carry your baby-that's it. Keep on top of your pain meds too!
For my next c-section, I plan on wearing a belly support/abdominal binder afterward. I used a pillow held against my belly every time I laughed or cried. It just helped to have support. I have already purchased one for next time. Get your doctor's ok before wearing one, though.
I had an emergency c-section a month before my due date. I was pumped full of fluids via IV as well, and it took a long time for the swelling to go away. However, I had pre-eclampsia, and that's why I had to deliver early. The pre-eclampsia caused the majority of my swelling post-partum, and by the 6-week mark, I had lost 30 lbs. of water retention. I could finally wear shoes again and get my rings on. My swelling situation wasn't normal, though!
I hate to mention this, but the belly over-hang (or apron, as c-section moms call it) doesn't always go away. I am now 5-months post-partum, and my gross belly hang is still there. I have tried everything. I now wear Reitmans comfort fit jeans (no zipper or buttons) and 'tuck' my flabby belly inside. Ewww. I have lost all my pregnancy weight, and I look the same I did before pregnancy...except that my stomach is hanging down. I've just accepted it.
Ok, I'll tell you my story about back pain after a c-section, but I don't want you to freak out. I'm just getting this out there in case someone else is reading this and going through the same thing. The pain you are experiencing in your back is exactly what I have. However, my pain set in about 3 months post-partum (not right away like yours). Mine is caused by the spinal block I had. It's so bad that I constantly visit the massage therapist and chiropractor for relief. I also can't sleep more than 3 hours at night without the back pain becoming soooo unbearable that I have to get up and walk it off. It's the most awful thing I've had to deal with. Nevermind the belly or the scar or anything else-the back pain is the worst for me. HOWEVER, I am sure this is rare and that your pain will go away soon!
As for pre-pregnancy shape, my uterus took about 9 weeks to go down! They say it should return to normal size by week 6, but even my doctor commented at my 6-week check-up that it still had not gone down. This can happen after a c-section. I was told that it can take up to 12 weeks for some women!
I felt pretty good by the 3-week mark! I felt like myself, but I still couldn't do much. By the 5-week mark, I still couldn't lift the carseat with my son in it. But my week 6, everything was great! I could lift the carseat, drive, and have sex
However, I will warn you, many women say that sex after a c-section is very painful the first few times. I was unfortunately one of those woman, but it does get better!