The baby is 15 days old, newborn, and often doesn't sleep at night…

The baby is 15 days old, newborn, and often doesn't sleep at night, crying, only calms down on my arms during the day he sleeps less, I am already very tired, not getting enough rest, I think that soon it will be night, it becomes scary, if someone holds him on their arms more or less calms down, I (mom) hold him on my arms and he cries, why? My firstborn, often because of this I worry, it's really bad in my soul, we also don't sleep in our room, in other rooms he sleeps more or less without light, it's hard to sleep, in the hospital for 3 days he slept well, please advise, is