Baby feeding bottle. Breast feeding?

Hello my son is 2 months old, he is mainly on breast feeding but we also give him formula in karori spoon, however late at nights he becomes whenever he breast feeds he goes off to sleep and then wakes up again when he is put in bed,we try to Kim him awake but no use he sleeps while feeding, also when we try to feed formula in karori soon he becomes very irritable, so two nights we tried feedng him in bottle he had and slept. So one time during the whole night can we feed him in bottle? Just giving him feeding bottle once can let him off breast feeding? As I want my child to be on breast feeding mainly but during night it is impossible at Times to breasts feed him, so can feed him via bottle once only in 24 hrs, will this wean baby from breast feeding? Plz suggest