To me Nembutal sounds like the most peaceful method but sadly it's not even avaliable, I think that something as beautiful as being able to pass away peacefully is something that is far too good to be true in such a hellish world, it's very cruel how suicide is so unnecessary difficult but sadly it's just the reality, there is too much pain in existing so we shouldn't have to suffer in our last moments. But anyway I hope that you find the freedom you wish for.