Needs suggestions

Lately my 3 year old daughter hasn’t been wanting to come home. Last weekend I allowed her to stay at my cousins with her daughters. She told my cousin that “I didn’t like her” and she didn’t want to come back home. When I got the phone call i cried my eyes out that night. Because I’m a single mom and I know I’m not perfect but I’m honestly trying so hard for them to have a better life. I have laid in bed every night crying myself to sleep since she spoke those words to my cousin Like what am I doing /not doing that makes her not want to come home? After school she sticks to her teacher leg and tell her she want to go home with her. The teacher made a comment today that crushed me, she said that my daughter was the only one that doesnt want to go home out of 22 kids. she don’t know what’s going on of course but it crushed me even more. I drove home balling my eyes out because it feels like I’m failing her. I don’t know what to do. I have tried talking to her to see why she’s saying those things and not wanting to come home and she just say she doesn’t know. At this point I will take any advise or pointers because I’m so lost right now and I don’t want her ever feeling that way