Have you tried seeing a chiro as well?
my daughter had reflux up to last month, she is 10 months old today
she was also on nexium and on novalac ar
I took her to the chiro for a few sessions when she was 3 months old and it really helped with the cramps etc, afterward i really saw a difference. my baby chiro also showed me a few ways to burp her in order to ease her pain etc - u can u tube him as well, dr mike marinus, there is a video on burping reflux babies
he also advised me to try iberogast, which helped with the constipation caused by the novalac and nexium
good luck!