5 month old wont sleep without nursing


My 5 month old is nursing dependent. She won't sleep, or nap, without nursing. Even when she gets fussy she is inconsolable unless nursed. Any tips for breaking this habit and getting her to nap without needing to be nursed? She sleeps through the whole night and wakes up once to nurse to get herself to sleep again. However, she is in the 4 month sleep regression (she just turned 5 months) and has been sleeping terribly lately.