I have been thinking about this thread all night and I would be completely petrified if I read this before my first child. Yes, having a baby is lifechanging and yes it can be hard. My first, as I said before, was quite frankly a complete nightmare and he didn't stop crying for 5 months but I still didn't find it as depressing as the picture so many people have painted.
For me, the key was to be organised. Before the birth do a batch of meals ie casseroles, bolognaise and curries so that you have something to eat, it IS hard to cook with a newborn. Have an online tesco order with all your basics and just press send weekly and you'll have staples
Go to Primark now and get some post pregnancy clothes such as leggings and tunics or some comfy sweats and tops and get dressed every morning before your partner goes to work. I have never stayed in my PJ's all day and I always advise friends to get dressed first thing and then you're ready to face the day, even if you go and have a sleep in your clothes. I had a bath / shower in the evening leaving DH to deal with screaming baby.
Keep a changing mat and changing stuff in the lounge as well as the bedroom so that you can do quick changes when they poo before leaving home without treking about the house.
As soon as you can get out everyday, check out post natal groups / breastfeeding groups, spy quite areas of your local coffee shop where you'll be able to feed discreetly now and put them on your fridge. Even the grumpiest babies will often settle on a walk or car drive.
Yes, you'll get caught out when when your baby poos on his clothes and you haven't got spares or the sticky bits will come off your last nappy but you'll become a pro at improvising or running into mothercare regularly but keep a spare of nappies / wipes/ cheapy babygrows in your car boot and buggy as well as your changing bag and you'll manage to sort something out.
It's hard and it's lifechanging but it doesn't have to be desperate and impossible at all even if you've got a grumpy baby like I had. My days with him were much easier if we got out and about and rest assured he grew out of it he's now the most delightful happy 7 year old I've ever met. We'll see if I eat my words when #3 arrives in a few months time