Nursing strike? Advice please!!

My 4 month old is very fussy in the day all of a sudden. As soon as I put her in the nursing position she pretty much screams. When I do manage to get her on she lasts 10 seconds before unlatching and looking around then going back on for a second then off again followed by more crying. Nothing physically has changed to cause this, but she’s not feeding well at all in the day. At night she is a dream. It’s been going on for a week now🙁 I’m worried we might have to end our journey early 🙁