Feeding my baby is so stressful

My baby has always been a bit fussy with feeding. She’s 12 weeks and bottle fed (has been since she was less than a week old). For the last few weeks, possibly more than a month, she’s started to turn her head away from the bottle (almost always to the left) and keeps coming off and on the bottle. This was happening occasionally (maybe a couple of feeds a day). For the last couple of days she’s been doing this every feed (7 times a day) and it’s becoming increasingly difficult to feed her and make sure she gets enough food. Shes also started fussing and crying a bit during feeds. She’s definitely hungry as she’s gasping for the bottle but then will pull off soon after she’s latched. We’ve recently increased the teat size so that’s not the problem. Has anyone experienced anything similar? It’s making me miserable as feeding is such a horrible experience and I dread it 😔 I’m doing my best to keep calm as I don’t want my stress to rub off on her but it’s so difficult.