Using opiod-level pain medications to experience relief is not normal. Also, it's extremely common for issues like endometriosis to run in families. My mother, grandmother, and sister experienced debilitating symptoms as well. Because they believed it was so normal, it made it harder for me to get a diagnosis.
I am so sorry you're experiencing that, and I'm glad a birth control pill is providing you with relief. Be aware that over time it may not prevent breakthrough cramps and bleeding - it eventually stopped working for me.
I know that because you've had to live with this a long time and it is normalized in your family, it seems fine. I encourage you to continue researching the causes of painful periods and considering that life without opiod use to manage period pain is not only possible, it is normal.
Take care,
Sarah