Baby won’t stop crying

J

This is my third baby and he is a bit over 3 weeks. He is never happy. Wakes up crying, is never happy or comfortable when awake. I can’t just put him down anywhere. My first two were nothing like this. He is feeding and gaining weight. But just unhappy. Don’t know what to do, thinking it might be colic/ reflux. Has anyone had any experience or have any advice?