I believe you already considered it, but here I go again.
If you fancy a short life? Then why not get into dangerous sports/games/some_other_shit?? that will kill you.
Here is the catch, it won't kill you if you will be smart about it. Plus You'd milk some fun from it, and it may as well supply you with a bit more reason to continue living.
Then if decide to commit suicide it will be in action, with will be 'considered as an accident'. (with I do not support, but shit still happens.)
BASE - Wing_Suit_Extreme_Fag_Example.jpg
(Drop a low cliff) [65% death.]
(Leap a much higher cliff) [25% death.]