I need some help telling my parents I’m not Christian

So I already posted this in r/advice. I need some help telling my parents that I’m not Christian. I feel like at this point in my life I should be able to choose my religion (16m). I’m getting tired of pretending I’m Christian when I’m not, I’m lying to the people I love and I feel like they think I am a totally different person than who I actually am. The reason I haven’t said anything is because I don’t want to upset them and I’m afraid they will think that they failed as Christian parents. I love my family but I feel like the longer I wait the worse off I am going to be when they inevitably find out. If anybody has advice it would be greatly appreciated.