Hi izel.kroeg
Our lg had reflux until she outgrown it at about 6 months. She was also on Nexium and I hated having to give her medicine everyday. For us, it was the only option that gave her full relief from reflux. It is heart breaking to see your little one in pain.

I can say that she suffered no side effects or other consequences from it.
I breastfed her and I found that cutting all dairy and soy from my diet did help a lot. She definitely had a sensitivity for dairy and soy and would spit up huge amounts after I ate anything with milk or soy in it. I did this for 6 months and it was extremely hard, there is dairy and soy in almost everything. You are basically stuck with only 'whole foods'. There seems to be a definite link between milk soy protein intolerance and reflux. Are you sure your lg is lactose intolerant? It could be a milk protein sensitivity, which is all dairy, not just the lactose.
My lg is now almost 8 months old and a happy little munchkin, she is still mostly breastfed and I have reintroduced dairy and soy in my diet with no ill effects (hooray!) and she takes one bottle of NAN H.A per day. She can even eat yoghurt.
I read somewhere that the time they outgrow reflux is linked to when they can sit independently. Hopefully this is not far off for you
You can also try giving smaller feeds more frequently so that it does not push up into her throat. Another trick is to keep baby upright for 30 minutes after feeding. This is easier said than done.
I found this website very useful for understanding and dealing with reflux:
www.refluxrebels.com/
Best of luck