Almost 4 months and sleep is just a far away dream

Hello everybody, maybe one of you can help me with any advice. My baby since she was two months started to sleep from 7:00 pm to almost 5:00 am, she was a champ on that part but since the three months and now a week away from 4 months, her sleep is just bad and crappie, she doesn’t sleep anymore like before, is very fussy and even though I’ve been veryconsistent with her routine still no progress. Any advice?? Is this normal?? I’m just a first time mom looking to see if i did something wrong or looking to do something better for my baby!!