Hi, When I first intro bottle to my son at 1 month old plus, he rejected too. I used about 2 weeks time to let him get used to bottle fed. Dont stop direct latch. Try using this method:- 1) Try slow flow teats and the similar teats to baby's pacifier (if baby is using it). 2) Let someone else bottle feed. If you are feeding your baby, higher chance of rejection because baby is smart to know you are direct latching him, not bottle feed. 3) Try feed with small amount first to let baby get used to it. 4) Put some breastmilk on the bottle's teats. It is safe to drink collagen supplement and drinks, and it is a bosster to breastmilk (booster for me).
If you want to continue direct latching baby when you are home, get someone else to feed the bottle. Mummy shouldn't be near when baby is being fed bottles as they can smell that we are around. If you want to stop direct latching altogether, stop latching and get someone else to feed the bottle until she is used to it then you can try to give bottles. It will be better if you bring the collagen supplements/drinks to the doctor and ask if the ingredients are safe. There are many types of collagen supplements/drinks in the market, some are safe and some are not. Best to ask for professional advice.