15. That was almost 13 years ago.
But... Here is the thing. If you read my posts, you might know I have this thing about "being an anime person", which sounds stupid, I know, but listen... Since I was very small, like 5 or so, I already spent most of my time within my head, fantasizing about being somewhere else, being someone different... Two decades later, and that hasn't changed, except... I realized how silly my dreams were when I was still a child (but I never gave up on them, of course - my dreams are all I have, aside from my dog).
Why I am saying this? Well, because when I realized I would have to stay in this world for my whole life, it didn't take long for death ideation to become a thing in my little head. Even as a preteen, I was already thinking about dying, disappearing. Then puberty came, and by the age of 15 if not a little earlier than that, I was already pretty much suicidal.