Ok Op, please breathe....you can do this particularly if you don't have money issues..
I had 2, 16 months apart, l was living newly overseas with a DH who travelled constantly, and gave absolutely no help at all when he was briefly home.
I had no family there and had not made any friends...
I had an emergency c-section with no one and a planned c-section with the second....
My dm flew over and helped for one week, then l was alone for 3 weeks before DH came back for 2 nights....
My lifesavers were.
Routines,
l loosely followed Gina Ford, so by the time DS came along, DD was in bed asleep by 7pm until 6am......really focus on good sleep training NOW for your toddler...l didn't feed on demand so feedtimes were consistant.
Organised house,
I had a town house, lots of stairs,
so l put a bassinett on each floor (so l could always put baby down somewhere safe), and a playpen on each floor so toddler could be put in with a toy.
I had a bigger playpen with all the toys in the kitchen, and in sight of a TV ( for essential distraction when feeding or cooking!) so toddler had a safe play area, and l could put baby down without risk from toddler.
Nappies, wipes and changing mat on each floor.
I used to put toddler in cot ( with a couple of toys )and baby on a pile of towels in the bathroom, in my view, once both were fed and changed in the morning, whilst l showered and washed my hair.
l had a cleaner, if you can afford it never will it be more appreciated!
Whilst pregnant l ruthlessly decluttered, and rearranged my home to make cleaning up easier, and imagined what l would need where when no 2 came along....
Food and nappy deliveries..
Acceptance that it would be full on for a while with no evenings out!
The good things were,
As it was largely myself and the dcs, l arranged my life to suit me,
l rarely had to cook for DH, so ate early to give myself precious downtime in the evenings ( by the time DS was 6 months he was going down to sleep, like DD, at 7pm in his own room with a monitor) He had a sleep feed and change at 10.30 then would sleep through till 5.30am.
I had from 7ish till 10.30 to myself....and slept from 11pm till 5.30am.
If l was really tired l would go to bed at 8pm till the 10.30 feed then go back to bed after.
Of course it doesn't always go to plan, but IMO trying to stick to a routine of sorts certainly makes life easier....
The other advantage was as sson as DS could crawl, they would entertain each other for hours, then they played for hours together as they got older, only now they are 12 and 11 do they clash!
All the way through l have had very little support and it is perfectly doable, just think how YOU want to do things, and also always look after your health, for me that was getting enough sleep.....
Congratulations on your pregnancy...you will be great!