Your condition sounds truly terrible. You have my sympathy.

It would be deeply unethical for me or anyone on this panel to try to discuss your particular situation in a forum like this. I would hope that you have a trusted friend or relative with whom you could discuss the matter, someone who knows you well, and who could serve as a sounding board as you work toward what has to be your own decision.

I will only make this observation: you certainly should not attempt to make any decision about this if your depression is not being treated adequately.

What I can do as a professional philosopher is to steer you toward some academic work that surveys and discusses the ethical issues involved. I suggest you read Robert Young's entry on "Voluntary Euthanasia", which you can access online at the Stanford Online Encyclopedia of Philosophy: http://plato.stanford.edu/entries/euthanasia-voluntary/ The article is mainly concerned with the social policy question of whether voluntary suicide should be legalized, but I think you'll find the arguments discussed to be relevant to your own situation as well.

Again, I am very sorry you are suffering so greatly.

I take it that you are talking about extreme and expensive technical measures to prolong life. These measures are of course artificial, but that in itself shouldn't count against them (what is wrong with, say, taking an 'artificial' pill for a headache rather than allowing the 'natural' pain to continue?). Is requesting those measures selfish? Well, we don't usually condemn as selfish those who spend resources even on comparatively trivial things -- such as CDs or cars. One's life is a condition for many if not all other goods, and most people believe that we have a right, other things being equal, to decide when it should end and in what way. Now it might be said that the resources being used to provide this kind of care could produce a whole lot more good elsewhere. But that point -- which seems to me a strong and important one -- applies to most expenditure, in the developed world at least, not to that on life-saving medicine in particular.