Ahhh I feel you, this is such a common worry among working mums! Honestly, at 1y6m dia dah boleh minum from cup or straw cup, so you don't have to force the bottle puting, a few of us just skipped straight to sippy cup or even normal cup with help and our kids adapted fine. Since you're planning to pump, maybe try introducing the cup method with expressed milk first so it's less of a shock for him? For the FM vs continue pumping, that's really personal, some mums I know maintain pumping schedule at work to keep BF going, while others transition to formula sebab convenience, and honestly both ways work lah as long as baby getting nutrition. I'd suggest perbincangan with your paediatrician about what works best for your situation, especially since anak dah established BF and you want smooth transition when you start work. Good luck, mama, the first few weeks balik kerja memang challenging tapi kids adapt faster than kita expect!