Day night mixed up

Hey all,
I delivered a beautiful baby boy on 31st May 2016.
My baby has reflux, for which he is currently on zantac & his evenings are so fussy, specially after feedings. All he wants to do in the evening after nursing is just cry & cry. Also, his nights are the worst, he refuses to sleep at night and go on sleeping the whole day long, so much so that i have to feed him when he is sleeping, dosent get up to eat even.
What can I do to make his evenings more pleasant as well as correct his day night confusion. Also I have tried bright lights & sound during the day and have kept him upright for 30 min after feeding. But none of these seem to help at all.
Thank yiu