My baby has acid reflux. HELP!

Daisy

My poor baby suffers from acid reflux he's 2 months old. Ped prescribed Zantac 1.2ml at night time. She also suggested adding rice cereal to his bottle. 1 tspn per oz she said but im kinda hesitant on trying it since he's only 2 months. He's currently on enfamil gentlease, also considering enfamil A.R. I'm just afraid it's going to cause him constipation, he's also a colicy baby afraid it will make his colic worse as well. Please help any suggestions or anyone have any experiences with either one. I just don't know what to do i can't even put him down when he's asleep because he will wake up within 5 min.