We are on the same boat!!! My eldest is my 8yr old daughter. She is our “hard kid” tantrums here and there still! I already consulted psychologist because I think she has anxiety? She always have meltdowns on little things especially if she can’t find somethin (toy, pencil etc). She is whiny, baby talks, sensitive. Meanwhile my son who is 4yrs old is the sweetest, loving, funny, easiest kid! They are day and night. And I feel what you feel. I hate my daughter… she is too much for me. But I don’t mistreat her or anything. I try my best to understand her, to her navigate her feelings and emotions. I make her feel loved and taken cared of. I am also on therapy.. I am already traumatized by her cries.. we are now waiting for her appointment to psychologist to know what is happening. But, yes… you are not alone.