Please any ideas

My son is 17 months old
Lately he will not settle at night cries and cries
He has always had a routine bath pjs warm milk and bed
He is just screaming constantly last night it was 4am when he finally went to
Sleep and was awake again at 8am   I am so tired
Any ideas on how to help him settle?? X

Try rocking him. That helped my first when he had trouble falling asleep

He won't let me rock him
Last night I tried
Juice,milk changing his nappy giving him his blanket and dummy
Tried him in my bed tried his cot into room tried taking him downstairs in a travel cot also on the couch nothing worked he finally fell asleep at 4am and he is the same again this evening I put him to bed at 7pm and it's now 9.22 pm and he still isn't asleep   I'm exhausted x

I would take him to the doctor maby he has a tummy ace or an ear infection.