When was your difficult child less difficult?

I’m at my wits end. I try to choose my battles. I try to choose positivity but my almost six year old is still draining me with the constant whining, fits, and just choosing difficulty. She said I hate her today because I got frustrated during her third tantrum of the day. It breaks my heart. I told her I don’t like her behavior but I always love her. I show her so much affection and tell her I love her all the time too. But I’m also finding myself avoidant and walking on egg shells around her. I don’t want to feel like this. Did your “difficult” child get easier because my oldest has been nothing like this.