S.T.
i'm not sure why you're so shocked. there are lots of 'new' things here. he's only had his own room for 3 weeks, and he just got tubes. suddenly instead of sleeping with mommy, he's being left to CIO for half an hour at a time.
instead of letting him scream for a half hour, then getting him up, then putting him back down to scream, why not go in to him after a few minutes but NOT get him up? sit with him, stroke him, murmur quietly to him. but screaming for that long releases all sorts of stress hormones, then getting up and having his routine disrupted, then back down to scream more- well, no wonder 'going to bed' has been branded a scary and unhappy thing for him.
babies go through phases. you can't expect your 1 year old to behave just like he did when he was 3 or 6 or 9 months.
stay calm, quiet, soothing, loving. don't leave him screaming. don't get him up and put him back down. sit with him quietly where he can see you, touch him gently. stay quiet. stay calm.
and what's in his bottle? it's probably past time to stop giving him anything in his bed, or water only if you must. but don't do it now, while everything still in an uproar.
khairete
S.