SOS HELP T.T

Hi mummies, My son is currently 4 months old going to be 5 this month. However he doesnt want or always fussy to drink milk when he is awake.. the only time he will drink is when he is half asleep. We tried changing the bottles from hegen, nuk and pigeon and still the same, even the milk powder from nan, enfamil and s26. He can sleep from 8pm onwards till 7am the next morning without milk which worries me.. Help, is this normal? Any tips to make it easier for him to drink milk?