I'm so sorry about your back labor—and that you had no idea what back labor was before it happened to you. But you are an Amazon warrior priestess slaying a dragon on the moon with an axe that is also a guitar. You are. Even though you feel like you did that time when you were three and you got separated from Mom in the elevator.
Trust me on this one.
It's okay to feel like a scared little kid, but remind yourself every day that you are motherfucking tough. You just did an amazing thing, growing and giving birth to this gorgeous baby. It's also totally okay to feel shitty and hate everything and wonder why you thought this was a good idea in the first place. Get yourself some Baby Blues Mood Remedy tincture and take it every day, even if you don't think you need it.
Your baby will sleep at night, and he'll do it sooner than you think. By the time he's eight months old, you will be laying him down in his crib at 8:00 PM every evening. You will tell him you love him, close the door, walk away, and he will sleep. And by the time he's five years old, he'll be saying things like, "Can we get started on the nighttime routine?" For real.
The reason you have so much trouble with diapers leaking? You're not doing it wrong. You just have the wrong diaper covers. Try Thirsties. They seem to work well for long, skinny babies like yours.
I know it can be hugely intimidating to leave the house with a tiny baby. Do it anyway. Get out of the house every day. There is a coffee shop walking distance from your apartment. Walk there! (Order something small if you're worried about the price of coffee-shop-coffee.)
Babies are really portable when they're tiny. Take advantage of this and go to a museum or a movie.
If you're out of the house and the baby seems hungry, just find a place to sit and feed him. It's totally alien to be someone's food source, but you don't need to be anxious. It won't hurt him to wait a few minutes while you locate a comfy(ish) spot. If you're driving and he's really hollering, it's okay to pull over somewhere and breast-feed him in the car.
Speaking of breastfeeding, it really will get easier. That awful thing he does right now where he struggles and cries and you have no idea if milk is coming out? He's just getting used to being on the outside. He's only five days old, after all. He is getting milk (the reason he looks bigger and more mature every day is because he is bigger!) and he'll really get the hang of it in just a couple more days. And very soon, breastfeeding won't feel quite so awkward. Nursing a three-month-old baby is 1,000 times easier than nursing a three-day-old or three-week-old. Just keep an eye on your wrists so they don't get all carpal-tunnely.
Not every snuffle or squeak from the baby means "I'm hungry and I need you!"
That being said, if your gut says to check on him, do it.
Don't even think about going back to work. Your job is not that great, and your commute is terrible. Quit now, and save yourself a lot of mental anguish. Which is not to say that being a stay-at-home parent is easy. It's not.
But, as we've established, you're fucking tough.