Baby won’t nap and always cries

My baby will be 7 weeks on Sunday. I never paid too much attention to his “schedule” before because I was always told newborns dont have a schedule but the last few days have been awful and I realized he will not nap..he is up 3-4 hours at a time and I can tell he gets so tired and will start to doze off but fights it and is miserable. Then if he does fall asleep it’s only for 15-30 mins. I have to constantly be carrying him but it’s literally killing my back and I don’t know what to do.

He also takes forever to get to sleep at night. They say to put a baby to bed sleepy but not fully asleep but he either only lasts 10 mins before screaming or instantly is wide awake again. And we’re back to doing laps carrying him. I have cried multiple times a day the last few days, idk what i’m doing wrong but I can’t keep doing this 😩