Have changed my response a bit as my kids are late teens and advice has changed...
If he’s feeding all day and never seems properly settled (rather than just normal cluster feeding), it might be worth considering reflux or CMPA (cows milk protein allergy).
Reflux can look like arching backwards, lots of hiccups/swallowing, seeming uncomfortable when laid flat, or feeding very frequently but not content. Holding upright for 20–30 mins after feeds and babywearing in the day can help.
Apparently tilting cot etc is not recommended anymore as isn't safe.
CMPA is more likely if there’s blood/mucus in poo, significant eczema, vomiting (mine didn't) or strong allergy history.
If you can’t put him down at all and you’re barely sleeping, that alone is reason to speak to your GP or health visitor and for them to take this seriously. Severe sleep deprivation is a health issue too and you deserve support.
If this feels more than "normal newborn stuff" it's sensible to push for help. Weight gain on paper can be unhelpful as showed they are thriving (which is good but doesn't get to the crux of the problem). So it's important to use the right phrasing to get them to take this seriously.
Instead of: “He cries all the time." say (if true) “He appears to be in pain/discomfort after most feeds - arching, stiffening and crying for X mins"
Mention sleep deprivation clearly: "I am getting about 3 hours of sleep in 48 hours because he can’t be put down. I’m concerned this isn’t sustainable or safe.”
Describe feeding behaviour precisely
“He feeds very frequently but doesn’t seem content afterwards.”
“He wants to feed again within 20–30 minutes and seems uncomfortable rather than hungry.”
If relevant, use any of these specific red-flag phrases for CMPA:
“There is mucus/blood in his stool.”
“He has significant eczema alongside the feeding issues.”
“He is vomiting large amounts after most feeds.”
“There is a strong family history of allergy.”
Any of these raise consideration of CMPA.
If you don't feel listened to, “I understand newborns cry, but this feels beyond typical unsettledness. I’d like this documented and reviewed.”
I don't want this post to be too long so I'll share some reflux tips in another post incase they're helpful.