Step 1: learn about what is and isn't meaningful, instead of uncritically assuming altruistic morality is true and devoting your life to doing what is "meaningful" according to some other people. Be your own guide instead of just assuming charity = meaningful.
I cant stand libertarian equivocation on the meaning of 'selfishness'. If your 'ethics' is predicated on not putting a high personal value on the wellbeing of others, you are the problem. If your 'selfishness' is seeking the fullness of your values while recognizing this needs to be reciprocated and you happen to not be a psychopath, good.
Definitions are not simply a matter of taste. They aren't validated by popularity, or authority, and we're individually responsible for the definitions we hold: each of us is the ultimate authority on definitions, in a sense: we each bear the responsibility for our own conceptualizing.
But that doesn't mean that concepts or definitions are subjective. Quite on the contrary: in order to be correct, definitions have to be induced from reality, just like like any true scientific concept (such as momentum, for example). The purpose of a definition also has to be kept in mind: definitions are what we use to mentally distinguish one concept from another.
Once you understand the above, you can see why it's really sensible to take the Objectivist stand on the word "self."
And for the same reason, you can see why we had to take words like "gay" and "queer" away from the bigots, who used them as epithets to smear hatred on good people. The bad rap that selfishness has with the culture today smears everyone. I think it's high time we fought back.
Read Atlas Shrugged.