Baby cries during feeding

My baby girl is 4weeks old, recently she has been fighting feedings by crying pushing away kicking her legs around and wailing her arms everywhere. She's hungry but won't take my breasts or a bottle. When i finally do get her to latch she will nurse on only one side then either fuss again, fall asleep, or spit up. This is extremely frustrating and I'm concerned she isn't getting enough. Anyone else experience this? I can't figure out what's going on with my baby!