Acid Reflux symptoms in 4 month old

Hi, My daughter is going to be 4 months old on Monday 5/27 and she has had acid reflux symptoms since she was about 5 weeks old. She is exclusively breastfed and I feed her every 2 hours during the day (every 3-4 hours at night)( smaller frequent feeds ). We keep her upright for at least 30 minutes after feeds and burp her as well. Though this has all helped her not spit up as much none of this has helped with the pain she has. We ended up starting her on Zantac a month and a half ago and it definitely helped the pain however it gives her frequent loose stools and insomnia.( We tried weaning her off and the stool becomes more normal again and she is able to sleep / nap much better). But when weaning the episodes of crying in pain return. She spits up a lot in general and her pain is usually during or after feeding. She cries/screams, arches her back, burps and coughs and sometimes even refuses to eat. We are at a loss for what to do to help her and have read about Nat Phos 6x as a possible treatment? We are hoping to try something more natural for her that will help with the pain but without as many side effects. We appreciate any advice/suggestions with this. I should also note that I have eliminated dairy from my diet - probably for the past month. I am also avoiding spicy and acidic foods as this seems to aggravate symptoms. Thanks !