My 4mth old boy used to drink 120ml every 3 hrs. But recently, he can only finish 70 -100ml per feed, regardless of day time or night time. He also cannot nap long in the day time. Naps are between 45mins to 1 hr. His bedtime is between 630pm to 730pm and he wakes up every 3 hrs. How can i help him to increase his milk intake and also to help him to sleep for longer stretch of hours at night?