I agree it could be teeth. Do not nurse or give her a bottle until AFTER she has eaten. Offer foods at regular times, like when she first wakes up, instead of straight tto formula or breast milk, give her solids. Mix with the cereal the breast milk or formula.
My son gave up baby food at this age and wanted what we had. So try scrambled cheesy eggs, diced up mini waffles or mini pancakes, fruit, yogurt, even cereal without milk. Lunches can be diced up sandwiches, cooled off mac and cheese, diced cheese, yogurt, pizza diced up.
Just keep offering things. Put it on her high chair and let her explore it herself. Make sure she is hungry.
Teething can cause pain and chewing hurts sometimes. Give her some natural teething tablets if she is slobbering a lot and has a lot of redness on her gums. She can show signs of teething way before teeth appear. Or try tylenol 30 minutes before your meals.
Keep offering it, they do go through phases and you just have to not quit trying.
Do not give her goldfish unless she eats something substantial. She will not starve, she won't. 30 oz at her age is a lot and enough to keep her full of nutrition, so encourage feeding solids first then liquids second.