My DD1 was 2 when my twins came. It was hard. No, it's not chaos forever! Newborns are so demanding; it won't always be so difficult. And your body is still recovering, so it's natural if you're feeling exhausted and frazzled. It'll come.
The reality of having more than one small child, though, is that you simply cannot be there when they cry every single time, right away, the way you could with one. You are only one person, and you can only do the best you can. The older child needs you, and the newborn will not be harmed if you set him down in a safe place for a few minutes to attend to the other child's needs.
We did a lot of sitting around while I was nursing. DD1 did watch some TV. If you decide to resort to the TV for a bit of the day, don't beat yourself up with guilt-- I'm the biggest no-TV advocate out there, and I let DD1 watch TONS when the twins were newborns. She's fine!
Have you been able to get outside at all? I don't know what the weather is like where you are, but long walks are what saved my life, once my body had recovered enough. We also sometimes went for car rides, not to go anywhere, but just to get out. The babies would fall asleep in the car, and then I'd take DD1 through a drive-through somewhere and buy her a lemonade, to make it a treat for her, and we'd all feel marginally better when we got home.
If you're not already babywearing, I would recommend that as a strategy. It gets your hands free, so that you can attend to other things without having to put baby down when baby doesn't want to be down. If you are struggling to learn how, you might pop into the babywearing forum for advice-- it may be that you haven't found the right carrier yet.
My strategy was to take life five minutes at a time, and to count it as a terrific day if everybody get fed, go their poops cleaned up and maybe had a nap. That was the extent of my expectations for myself. If we got through five minutes without catastrophe, then I set the goal of getting through another five. And before I knew it, the babies were sitting up and taking an interest in the older child's doings, and it's gotten steadily easier since then. (They're 6, 3, and 3 now.)
Hang in there! Be forgiving of yourself! And congratulations on the new arrival, too!