Morality, or Self-Preservation?

Epistemic status: I think the idea that follows might be worth pursuing, but I'm less sure about it than other things I post. I think it would be maybe useful in political discussions, in cases where there is time to deliberate. I guess it could be used on a more personal level as well. But I haven't thought through whether it would really be practical to implement.

I'm not sure the following is an exhaustive list, but I think that people can be motivated by: moral idealism, evil, and self-preservation.

If we are trying to justify our behavior, attitudes, and so on, we can't use evil -- we'll say that evil things are by definition unjustified and thus not grounds for justifying anything else.

So we're left with moral idealism and self-preservation. (Opening for objection: maybe there are other options?)

If that's the case, then we should have to declare how much of our behavior, attitudes, etc. are motivated by moral idealism and how much of them are motivated by self-preservation. If a given behavior or attitude is complex, which part of it is motivated by what, and for each individual part, if it is simple, what percentage "morally idealistic" is it versus "self-preservative".

Then, if we rely on moral idealism to justify ourselves, we need to cite which moral foundation we are using, and bind ourselves to the implications that follow from that moral foundation.

Arguably, self-preservation is only a valid reason to do things if self-preservation itself is grounded in a moral foundation. So maybe any proposed course of action involved in a serious decision needs to be morally justified. Perhaps moral idealism "sticks its neck out" as being moral more obviously than self-preservation. Self-preservation might not claim to be moral and evade notice. But strictly speaking, self-preservation also needs to be justified.

How can morality be valid if morality doesn't really exist (moral anti-realism)? And what would it take for something like morality to exist? What is the character of morality, what or who is it? What does it want (or "want")?