People who have cut family members out of their lives, what was the final straw?

My biological father. Some back story; My real dad was never part of my life and I grew up with my step dad since I was 6 years old. Went through the standard, I hate you and you aren't my real dad phase in life. When I was 10 years old I finally got in contact with my real dad through my grandma on that side of the family. I started visiting on the weekends. Everything was great and I eventually moved with my real dad. He would smoke weed and get drunk almost everyday, sounds cool right, what more would a 10 year old think besides my dad drinks and does cool stuff. Not the case. Most of the time I was getting raised by my step mom. Which is whatever but she started controlling my life hardcore. I am talking about I couldn't hang with friends during the week, if I got lower than an A in any of my classes she would start crying to my real father that I am pushing her to her limits and I am a troubled child. So I started getting grounded for weeks on end and unable to do anything. They wouldn't let me call my real mom or step dad anytime, as I was grounded. But the finally straw was probably Father's day. My dad was really into Nascar and he went to the race. We went to go visit him at the track and he was drunk and high. I didn't know it was Father's day off the top of my head. He came up and said, "Don't you have something to say to me?" Me always being grounded and thought of as a bad kid I said, "No." Thinking that there was something I was in trouble for. He told me to fuck off and that I am a piece of shit for not loving him. Proceeded to give me the bird and walked away. I pretended to go to the bathroom, went and borrowed a strangers phone called my real mom and told her to come pick me up. Never looked back since. Just toxic behavior and it really fucked me up for a good 10 years. I got over it when they tried to add me on Facebook when I was 19/20 ish then proceeded to say I am a shitty son for not adding them on facebook. I blocked them and haven't talked to them since.

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