Does anyone here know how to make poison, such as potassium cyanide or ricin, at home with easily obtainable materials? I am not planning to use this to harm anyone else, i just want to have the recipe handy for when i get to the point where I am done with all the things in my life and I want to leave. If I can't use poison, most likely I will resort to either jumping from a building or hanging, both of which would cause a commotion/be really disturbing for anyone who finds me. I'd much rather go peacefully and with certainty. If you have any ideas, please help.

P. S. Yes I have already sought help, and have been seeking help since I was 16. It has been a long, tiring, and completely unfruitful psychological therapy/medical therapy journey and I am just so tired. Please help.