It's hard when you are on your own like that, and you are at a really difficult stage as newborns are so demanding.
The obvious thing to say is, a baby is a full time job so don't worry too much about "getting things done". It does sound like moving house at this moment in time might be quite a big task, so perhaps it's something to contemplate for 2022 when the baby is bigger and you have more energy back
Honestly it does get easier. Baby groups are starting up again - my local NCT is back to doing free drop in coffee mornings, worth looking on FB to see what's going on near you and make the effort to go, even if you feel awkward and don't immediately click with he other mums, as lots of different people will go to the sessions.
Also try and go for a walk every day - is there a park near you, or a little playground, or a supermarket you could walk to?
Last tip, do look on eBay for a baby sling, they are fantastic and very cheap.
If your family is far away, is there any chance they could drive over to you (with a car seat) and you could go and stay there for a week for a holiday?