Third child fears

I am so ecstatic to be thinking we are adding another cute, fat baby to our family (yeah I know they dont stay that way but still) and due to everything thats happened recently I have been walking on rainbows and clouds as to how this is going to work with my life, my existing family and the future, but all of sudden on a particularly bad day when the toddler wouldn't eat her dinner for the 12837572746th time and the baby decided she'd go without a nap I suddenly thought, holy crap, there is going to be another one to add to the mix in 4 odd months time - CRAP!

So how IS a third going to make a difference - I mean, my time seems STRETCHED to the maximum as it is, I'm trying to physically work out where I might find another 5+hours a day to dedicate to a newborn... where's Hermiones time turner when you need it huh?! Currently there are times when I feel like I dont have enough hands, normally when the toddlers bum needs wiping but you can guarantee Im feeding Paige (and you dont stop feeding Paige if u want a quiet life) I only have TWO hands, not three, just two so my maths isn't all that great but even I can tell Im one hand down in this equation.
Routine... routine seems to work well with the two, yknow Liv gets all the attention whilst Paige slots in rather nicely and only lets me know she needs something with the occasional moan - fine, sorted, but WHAT HAPPENS when you add a newborn into this equation too? It was oh so easy to placate Liv when Paige was born with a bowl of sweets or ice lollies (Yep, I'm that mum) and admittedly she adored baby Paige so it kinda fitted in nicely, but oh my gosh, what will I do whilst Im trying to nurse a newborn and Liv needs food, Paige needs food - like logistically HOW DOES IT WORK!!?!?
What will happen to my eyes when I really am not getting ANY sleep. Paige has been a walk in the park compared to the shit storm that was Liv when she was born, and well, Liv she disputes sleep even now so I am well and truly up against it third time round surely?
What will happen when I take them to the park? how on earth do you watch 3 children!? how do you keep an eye on them - surely the law of averages says that one kid is going to fall off something and hurt themselves in this situation?
How do you tag team 3 kids? right now Mark tends to deal more with Liv and I'm a servent to Paige so err, the third one? who has that???
How do you fit them all in a car? Like can you? what are the rules hey?
According to recent research it says that families of three children are considered the most stressed, some considering having a third child as an indulgence (which I firmly disagree with) with some even believing that the third child is in fact a 'third wheel' in the family which horrifies me!
For me, having this third child feels so stupidly, ridiculously RIGHT. Like I've always dreamed of having 3 children, that and the fact that I miss the newborn stage as soon as they reach 6 months. But really, despite the above, I am actually so excited to be welcoming another face to the table, another smile to the photo's, another set of teeny tiny feet to walk in the sand with me, another hand to fit into mine and more arms to slip round my neck for a cuddle. I'd be stupid to think there weren't stressful times ahead but Im feeling oh so ready for this new challenge. However if anyone DOES have answers to the above questions feel free to let me know!