Don't do it!

Never mind your family. If the idea is to make them feel guilty, and make them think "gee, I should have gave John-117 more attention" or something, then it won't work - they would have to be 's to let you get like that in the first place, they won't feel much guilt. On the other hand, they may not be as bad as you think (you could give us a bit more to go on), so you wouldn't need to die for them in the first place.

I'm guessing your fairly young otherwise you wouldn't be suicidal over your family - in which case I think you should just wait till you are old enough to leave home. You kill yourself now and you will only have had a short crappy lifetime under them. If you hold on a little bit, you can live out your life the way you want - make friends do whatever, all without them bothering you.

And to tide you over until then, you have TW!