Baby not sleeping at night

Is anyone else's LO not sleeping at night? My Lo had put herself on a schedule. By 9 she would be down untill at least 3am or if she wake up at 12am to eat she would sleep untill 6. But she would sleep at a certain time. NOW shes not wanting to sleep at night takes cat naps all day and fights her sleep. Then im useless in the morning. Cant do nothing bc i need to rest. Coffee is starting not to do anything. My eyes are literally hurting. Tell me im not alone. 😢