JFB three kids has taught me that the first 6 months after a baby arrives are pretty much about survival - getting through the day with everyone fed, watered, bathed, bums and noses wiped, and trying your damnedest to get a few smiles occasionally from one or both of them. Some days I don't succeed and others I get a few smiles. Some days I will be driving the car on the morning school run with kids in tears feeling like an utter failure, and wondering what went wrong.
But most days are wonderful now, and once you find your groove you'll be fine. I think I said a few months ago that I try and take pleasure in the really small things my kids do that make me or them laugh, like Marc constantly aiming his meals at the dog's head (usually getting a direct hit), and watching him and the girls go into fits of laughter, rather than stressing over the fact he's not eating.
washing is my one headache so (if I hang) I hang very carefully, and finish most things off in the dryer with tumbler dryer sheets that are impregnated with fabric softener, so I don't need to iron the clothes and they still look presentable - I try and find as many short cuts to doing things as I can - but it's bl00dy hard work.
We had a swing for Marc which sadly he loathed - I was praying that would be my saving grace. In the end he spent most of his time in either the baby bjorn or in the bouncer, and was fine so long as he could see me and I kept moving him about the place. Can you try E in the baby bjorn? I got one with the extra back support and it was great. I never found the Ergo comfortable for me, but as Scarlett hated it probably didn't persist enough. Your back will probably hurt at first while it gets used to carrying the weight, but in a week or 2 you should be fine.
Sounds like you're doing a brilliant job.