Just a few years ago, I was technically suicidal, but never intended on acting on it (or even telling anyone). I was a Christian at the time and was under the impression that people who commit suicide go to Hell. There's many things to be said on the topic of Christianity's bizarre beliefs and practices, but I will leave it at this: guilt-tripping only leads down a dark road.
Child-me had a very big imagination. It was so vast with fairly detailed world-building. It was to a point where I enjoyed living in my own mind more than in "Earth". I was pretty creative and even wrote a few books. Looking back on it, some of my storylines and characters from grade school and middle school are better than ones I make now.
My dreams formed a fanciful future for myself in which I'd be a well-respected show creator or a successful (not exactly "famous") author.
To make a long story short, I realized more truths about the world and all the issues of it.
Bad will forever outweigh good.
There is no such thing as unconditional love.
Every one is there you except when it doesn't benefit them.
Life is a curse and an unnecessary cruelty. People who reproduce are selfish and honestly disgusting.
Friendship is a toxic distraction.
I went through several existential crises, but no longer have any. Life has no meaning, and that is all. Any meanings people assign to life is just self-manipulation.