My daughter is gonna be 2 months old on the 18th. She started off on similac pro advance, I tried to breast feed but it didn’t work out.

She was fine with the pro advance for a couple of weeks and then she started spitting up constantly. At her 1 month check up, I brought it up and the doctor said she has acid reflux and prescribed her Zantac and said to switch to pro sensitive. She was doing great on it until recently where she’s spitting chunky milk out and is extremely constipated. Her poop has been hard balls for 3 days even with the little bit of apple juice the doctor suggested. Last night she was screaming and crying from 11 pm to 3 am today until she fell asleep finally. I called her doctor first thing in the morning and was told to bring her in, now she’s on similac alimentum I’m just so overwhelmed with it all. Has anyone else had this problem??