Baby is wide awake after I feed her at night!

We got up a little after 1am for the first night feeding. She nursed for about 30 mins and drained my boob. I burped her and swaddled her and sang to her, walked her around the house for what seemed like forever, tried nursing her again, tried the pacifier, tried laying her in her bassinet and rocking her, tried the bouncer, tried just cuddling and now it's 4:35am and she's still awake. She's not crying or anything...just alert and wide awake. I'm so beyond tired. Anyone else's babies do this? How do you get them to go back to sleep? FTM here. Baby is 6 weeks old.