SEVERE Acid Reflux at 13?

im 13 and last year i got diagnosed with acid reflux. since then, i took zantac 150 once every morning. this past november it started to get worse so my doctor prescribed me zantac 150 twice a day- morning AND night every day. im still taking that. then in january it worsened even more, pain where i can't sleep which causes fever, i feel sick, and i could barely eat a full meal. my doctor told my mom to bring me to a stomach doctor at a local childrens hospital. she told me to eat a small meal every 3 hours. and she ordered me an endoscopy which i got early april. no tumor, by BAD, SEVERE inflammation in my stomach. since then, it still got worse. i developed bad lower back/kidney pain, severe abdominal pain, headaches (from behind my eyes to down behind my ears and down my neck), vomiting, fevers, dizzy spells/fainting, and worsened stomach (under my left rib) and chest pain. my doctor suspected stomach cancer twice, blood results came back normal. but now, everything is worsening and i feel light headed most of the day, some days so dizzy i faint. and im loosing weight constantly. i went from 104 to 100 since mid-may. my next stomach doctor appointment is july 1st. does anyone know why my pain could be worsening (preferably someone who has acid reflux/GERD)? any tips to sooth the pain?