Feedings

My daughter is 5 months old she has severe reflux and has gotten cereal in her bottles since she was 3 months old. She eats about 5oz every 3ish hours. She gets between 20-25 oz a day on average about 22 oz. She just started purees and absolutely loves them but the past few days she has been refusing her bottles. I just put her to bed and she only had 18 oz for the entire day and now she won't have a bottle until about 9 am tomorrow. I don't know why she isn't eating. Each day it's getting worse and worse. She is also teething so I don't know if that has something to do with it. Earlier when she refused the bottle after 3 oz I tried giving her sweet potatoes and she ate 2 TBS. So she is clearly hungry. Could it just be that the sucking is hurting her mouth? And is it okay that she only had 18 oz for the entire day?