I don't exactly know what to title this

I wonder what drives us to do what we do. Why at times we cannot think "clearly". Right now I know I am not thinking clearly, I haven't been since thursday, I've had a bad event that happened  to me lately on my mind constantly. 
What happened was I was cutting pretty badly, I started to bleed pretty badly, and…… I decided to write a suicide note. I wasn't planning on specifically killing myself, but I had been thinking about what if I died from this tonight. If I died, I wanted a few people to know that I hadn't been planning this, and that there was nothing anyone could have done. I wanted people to know that this mainly was self harm that turned directly into an accidental suicide.
And even now, to tell the truth, if I were to die right at this very moment, I wouldn't care much. I would have wanted to leave something behind, and maybe I will. Maybe I will write a letter, leave it saved here on my laptop, prepare a short letter explaining how to find it on my laptop. But only so that my last words won't be locked away on this machine. 
I am most definitely not okay anymore.