hi. my daughter's just done this. she was 23mths. maybe it's a stage! that's what they say about everything! it settled back to normal after about 4weeks. nothing wrong with her. she was clinging on at bed time and didn't want to be put down. she just screamed when i put her in her cot! and kept screaming! didn't get so bad she was sick but everyone's different. i went in to check on her after 5 mins and left her again. kind of went back to controlled crying. after a few nights she didn't want a bed time cuddle, just screamed and tried to wriggle away so i just put her in her cot and left! didn't know what else to do with her really. didn't want a cuddle, didn't want me to leave so i left! started as i meant to go on!! then she went to still not wanting a cuddle but going in bed happy then crying for a few mins when i shut the door, now this week she's back to her night time cuddle. who knows??
i did give her calpol a few times. she screamed that much she was saying ow and holding her ears but i do think it was from crying and bunging all her tubes up and not illness as she started doing this after about 20mins of crying.
maybe he's started to be scared for some reason, shadows? mine noticed them about 20mths, didn't take much notice of them before. we kept waving at them and played hidi boo, then she lost interest after a while.
she also wouldn't go to bed until my other daughter went, they share. she was having a right old tantrum if we took her up without her sis! now they go at the same time and do bedtime routine together. they have a cuddle and a story in big sis's bed before she gets in her cot but we did have screams when it was time for her to get in her cot.
so maybe he needs a change of routine now his age is different? the problem is finding out what he wants!! try a few changes like we did and see if you can find something that makes him happy. but like i say, it's took us a while.