Aiyo, I get it, memang stressful jugak transition ni! A few of my mum friends yang dalam situation sama try introducing the bottle gradually, maybe when baby is drowsy or after breastfeeding session, so dia tak frustrated sangat. One trick yang kawan aku swear by is using a bottle dengan nipple yang texture sama macam breastfeeding, slower flow makes a difference, and sometimes pakai expressed milk so baby tau it's the same thing, just from different source, lol.