Your family dynamic sounds very similar to mine. My father is or was or is an alcoholic. My parents split up about 10 years ago. I'm the oldest of 3 from them. I was about 23 when the split occured. My brother is 1e years younger than me and my sister is 15 years younger than me.
While the split between my parents was my mother's choice. She blamed his alcoholism for the reason she cheated on him (excuses). Growing up, my mother did a fantastic job at hiding the truth from us before the divo