My baby is 4 months, will be 5 on the 7th. He used to only go to sleep by being rocked by me then sleeping on me. Now he screams and screams until I hand him to his dad who does the same as me and he calms down and falls asleep in minutes. I'm struggling because it feels like he's totally rejecting me. He has had a bit of a personality change over the last week, lots of crying and unhappiness. What is this? 4m sleep regression? I thought teething maybe but calpol not helping. Does he hate me :(