Feeding problems

Hi my baby is 4months old now. I have stopped breastfeeding because sadly im no longer producing anymore breastmilk. I have this problem of my baby refusing to drink her formula milk. Yesterday she went 12hrs without drinking milk. Today she went on 7hrs without feeding. However she is still very active and her daily antics are all normal n okay. I have changed her formula three times. Changed bottles and teats 5 times. Still no changes. She has been acting this way since she was 2 months old. But she was still able to be fed after 1-2 hrs of trying to feed her. But now at 4months, she will cry bloodymary everytime i tried feeding her. She will refuse all types of teats too except for her pacifier. How do i deal with this? I am really scared she is malnourished and dehydrated. Help me please.#firstbaby #pleasehelp #advice