Sleep/eating regression??

Ugh I need some HELP! FTM...she’s always been such a good eater, not picky at all, and takes a sippy or bottle any time it’s offered. Up until about 3 weeks ago, she was sleeping through the night and only BFing before sleep and when she first woke up. But all of a sudden she will hardly eat ANYTHING, only wants to nurse and is sleeping so badly at night! Wakes up a ton and it’s a STRUGGLE to get her to sleep. Super fussy and throws fits all day long... 😩 I’m trying not to be stressed or upset and make it worse but I’m at my wits end...I’m exhausted and at a loss of what to do 😔😔 any advice is welcome, thanks in advance! ♥️