Breastfeeding strike?

Girls, I am at my wits end. My baby girl is gonna be 4 months in a couple days, she is exclusively breastfed and lately when she shows signs of hunger, I go to feed her and she is THRASHING and squirming and her hand is grabbing at my shirt furiously. The only thing that calms her down is patting her on the butt or holding her hand that is waving around like a mad woman and then she’ll feed for about 5-6 minutes (her usual is 10 minutes) and then she falls asleep. What is happening?! I’m very worried she’s starting to refuse the breast. She’s also been fussy way more than usual all day everyday. She’s crying and whining more than she’s happy.