What the quickest painless way of take my life?

There isnt really one. If you do it yourself, it may take some time or you could screw it up and have to live with a messed up body. You would have to hire somone to sneak up and shoot you in the back of the head. Iv learned its best just to try and change the way you feel. Maybe change your environment or figure out whats causing the stress and defeat it. As soon as your at the point of setting up your own execution youl start thinking of your life and all the people who were in it. It makes it even harder. Its easier just to try to find change.