Reflux /breastfeeding ?

My baby girl is now 9 weeks old and over the past 2 weeks has really been wayy more fussy, not sleeping well and just cries like she's in pain. At her appointment she got her first shots last week and i brought it up to the doctor and she had us start Zantac. . Has anyone had good results with this medicine? Does it help with the spitting up and fussinessm