6 week old will not sleep

Amanda • 22. Married 💍. 3 year old son. Due with baby #2 July 5th 2016.
He grunts and fusses all night. I start tryin to get him down at 9 and he stays wide awake the whole time until midnight. We EBF and I nurse him to sleep then as soon as I lay him down (yes he's swaddled) he opens his eyes and starts the grunting. He's had gas drops and everything I know how to do. He sleeps fine during the day and were loud and it's bright so he knows it's day time and at bed time we dim the lights and are super quiet. Anybody have any advice?