It WILL get easier.
You started your mat leave early.
Your DBaby arrived early.
You had no time to adjust to being off work before DBaby arrived.
You may not have had time to say your goodbyes at work (I'm guessing).
So all of those put together are enough to knock you for six, especially if it wasn't planned that way. Quite apart from recovering from major surgery and having a newborn in the house, and dealing with the lack of sleep that a newborn brings.
The first few weeks (I'm not going to put a number on those) are a blur. But get some fresh air and a walk if you can most days - as much as you feel capable of (bearing in mind the surgery recovery). And just work on minding yourself and your newborn now.
Ask your DH to keep the show on the road in terms of feeding you and minding the house. And any others around who can help - can they hang out laundry, or make a lunch/dinner to drop in, or make you some tea and keep you company while you feed the baby (however you feed it).
As you get more into a routine (whatever works for YOU - not something from a book I mean), and you can see gaps between feeds and changes and all things purely baby-focused, you can start to do things like making proper lunch again for you, and getting things organized for dinner, and doing a load of laundry.
As babies get a bit bigger, they take longer naps, and while they still need lots of care - you can get times to just play with them, and also to put them down while you get on with stuff.
I used to wait until after breakfast and DH was gone to work, and after DD's next feed, before making our bed every day - I could pop DD propped up between the pillows and make a game of flapping the sheets and giving her tickles, while making the bed. OK it took 20 minutes instead of 2 when heading out to work - but it was fun time too.
And I had DD sitting up in her high chair, and I would talk away to her, beside the work top while I did kitchen things (cleaning or meal prep etc).
And you can start to get out to groups or classes nearby, or just meet up with a friend/family member for a coffee in a coffee shop. Not just sitting at home all day.
The newborn days are exhausting, even when you are "prepared" for them.
So give yourself a break, you are doing great, and it will start to slow down and take shape in the next little while - just give everything time to settle, make sure that both you and the baby eat and sleep enough, and then start to work on the other stuff, one step at a time.