You just said you were a moral universalist—that goes against the concept of there being a "your" morality. Either morals are universal (in which case, you don't need a specific living being to ask in order to figure them out), or they're, at least in some part, subjective. Further, you seem to be explicitly arguing against yourself with the "in one of the alternatives I wouldn't exist" statement—what system of universal morals would privilege your existence over the existence of someone who is better in every way, except for not being you?

What I said above was that "morals or utility" are subjective to an individual—which agrees with your point. I said "and thus don't really exist" because the definitions for epistemic morality or universal utilitarianism require them to be universal—and they're not, so they don't exist as defined. (And a system that accepts subjective morality is usually just called "ethics", by the way.)