My DD, who turned 12 mths on the 8th of Aug, has 2 milk feeds a day. They are both out of a 'bottle' but they don't have teats on them, we use the green 6m+ toddler spouts from Avent. We've had no problem with the change from teats to spouts and to be honest my DD didn't even seem to notice. Although we did have to try 4 different types of toddler spout/cup before we settled with the Avent. I'm sure that I'm one of the lucky ones and that it really does depend on your child.
At the complete other end of the scale, my StepDS had a bottle until he was 5 ( a comfort thing). It must have been infuriating for DH as he was keen for SDS to give it up but DH's ex-wife used to just keep giving him the bottle for a quiet life (she has admitted this).
On the subject of 'I'm a baby...', I think this is a fairly common stage in toddler-hood. Kind of a final farewell to the baby years. Try not to worry too much about it.
P.S. Apologies to those who are seeing this for the second time, I posted it on the other thread too.