Hang in there. It really does sound like things aren't going as badly as you think.
Find a comfy position, ideally in the lounge in front of the TV with easy access to the kitchen! I found that sitting upright with DD in cradle hold worked well for us after my EMCS. And be prepared to stay there and have people bring you food and drinks.
Are you taking your painkillers regularly? Do. And if you can't shower every day, wipe your wound with sterile saline to keep it clean - you don't want it getting infected!
If you're getting lots of wet and dirty nappies and her weight is doing okay, she's getting plenty of milk. Suckling lots (even if there is little milk) is how babies increase your supply, so try to just go with it. Basically the first 10 days after your milk comes in is one big growth spurt. It won't be like that forever, I promise!
If you can feed lying down (I couldn't soon after the CS but some people find it easier) then do. It really helps when you're getting knackered.
And do as little as possible generally. You've just had a major op and have another being who is dependent on you. You'll need help with everything for a little bit, so rope in family and friends to come round and make tea/lunch/dinner/hoover/etc.