BellaLily... I don't have much advice (actually none!! haha)...
But I just wanted to say I know what you're going through. Our DD was amazing... she was settled and happy during the day and slept well at night. I don't think we ever quite experienced what a newborn is like, because she was so good.
DS (7.5 weeks) was unsettled on and off for the first 5-6 weeks, and I was the same. Could not put him down because he would cry, and my poor DD was not getting what she needed from me so has started playing up a little.
There is light though... we've had a full week and a half of great day sleeps, laughing, smiling and just being wonderful before going back down for his next sleep. Also only getting up once each night!!! I've been smiling much more during the days too now Now I spend his day sleeps playing with her, and she is so much more calm
Best of luck!!!