Ay kakapagod talaga yan, mama! At 1yr2mo, okay pa rin siya sa breastfeeding kaya don't stress too much, marami sa amin na nangyari ang ganyan, especially kung matagal siyang all-boob lang. Try a different teat shape (like the soft silicone ones na mas parang breast), or warm ang formula slightly kasi minsan bet nila ang init, at most importantly, let someone else (not you) try offering it when siya calm, kaya minsan babies ay mas willing kung hindi kami ang nag-offer dahil alam nila may lasa kami. One of my mum friends swears na pagka-relaxed lang, sa couch habang nanonood ng tablet, biglang sumupsop na ang baby niya, parang walang pressure. If after a few weeks pa rin walang progress, best to check with your pedia dahil baka may oral sensory issue o something na kailangan i-address, pero most of the time it's just timing at patience lang talaga!