Welcome, Wing! Definitely a sneeze birth there. I'm also a bit too chicken for a home birth. Give me the hospital bed and the good drugs any day. 
SoYo it does get better, I promise. It's just that no one can tell you exactly when. But you never met a five year old that couldn't sleep more than an hour without a boob in their mouth, did you? Practical advice: inform DH that evenings are his affair. Leave him with baby and bottle and get a few hours' kip, out of earshot if you can. You'll have a broken night once he goes to bed, but those few hours will do wonders for your sanity. And if you've any friends or family around who want to help, hand them baby and bottle for a few hours, or if they're no good with babies, send them out for a very long walk with the puppy.
JoJo nine hours at four weeks?! I am jealous as hell! Mine absolutely will not go more than five hours (and that's a rarity; three to four is more common, and that's from one feed to the next, not actual sleep). And I know the feeling about every tiny noise waking you up. Is anyone actually intending to keep their baby in with them for six months as recommended by professionals who don't have to try sleeping next to the noisy little buggers?
Glad the nipple shields are working well, leni. And glad at least some of us are managing this breastfeeding lark! And same advice re: sleep as for SoYo. Designate a few hours in the day where OH is in charge, and you get your head down. Sure he needs his sleep because he's at work, but you need sleep too. Either one of you can be well rested while the other cracks up from lack of sleep, or you can both be a bit knackered. The latter is definitely preferable. 
Of course, the one downside to "man looks after baby while knackered mother sleeps" is when they sleep through a screaming fit. I went up to bed at half eight last night, expecting the baby to be fed about 10pm and 1am, then deposited in the basket upstairs with me. Half past three, I woke up to hear the baby screaming like a banshee. Figured she was mid nappy change, or grumpy about the slow milk service in this house, or similar, but the screaming didn't stop, so I went to investigate. Baby shouting her head off in the downstairs basket, man flat out and snoring on the sofa. Resisted the urge to go ballistic at him, but he's still snoring on the sofa and it's keeping the baby awake now...