With this as your firm standpoint I guess concepts such as the common good and the like won't apply to you. I like that you don't sugarcoat it though.
You know only what is common, not what is good. If you think self-sacrifice is good, then go forth and destroy yourself in the name of others.
Altruism is a very primeval and basic means of control. It's refutation is simple.
If you are an altruist, then you live only for the benefit of others. And yet others can always benefit from having the things you have right now. Others might eat your food, live in your house, and breathe your air. Therefore if you are to be an altruist you should rightly kill yourself.
As I have said many times: altruism is the philosophy of death. There is nothing more evil than a form of brainwashing that turns the human conscience against man himself. No longer does one's conscience say "stealing is wrong", but rather "you are wrong". Under altruism, existence is the original sin for which one must constantly atone. Hence altruism is a code of non-existence; For in order to be good, you cannot
be at all.
If you think a moral standard which holds non-existence as its highest ideal to be a good idea then to be consistent you must now take the advice given above.
As to whether or not it is a moral position to donate your organs, after some contemplation I have decided that not donating your organs does not constitute an act which is subject to moral assessment, as it involves only one person. However if you do decide to grant additional life to another, then this is a moral proposition, because now you must ensure that the person to whom you are granting life will use that time honorably, and not in the service of base and criminal ends.
In particular, in my case, there is a great probability that my donated organs would go to one of the very same bigoted socialists who aided in severely repressing the voluntary healthcare industry in the first-place, which in turn put they themselves in need of such donations; Hence these are not the deserving poor. And being as I hold all justice to be a moral good, and being as meta-physical justice is a subset of justice, it would be immoral and improper to shield such people from the consequences of the vicious and ruinious doctrines they hold. I would, in effect, be bailing-out those (or one of those) same fat headed socialists who keep this system going, and, in so doing, be hurting those other innocent people who might also become victim to this system. Needless to say, I can always sign a bill of transfer on my deathbed, if someone worthy of my organs comes along at the last minute. My expectation is that no such person will come along, therefore my default position would be to not transfer my organs to any other.