My son is a late pre term born at 35 weeks with a poor suckle reflex since birth and short NICU stay. So far I have offered him expressed milk and formula top up when needed. Now at 7 weeks with a lot of practice he has finally latched. However, he nurses for hour long stretches for 2-3 feeds, rest he is done in 20-40 minutes tops. Of his total 8 feeds, for 3 I still need to give him formula. How do I optimise feeds on breastfeeding solely? How do I transition to exclusive breastfeeding? Or is it too late since he is already 2 months old?