It depends on how you disproved my morality.

As far as I can tell, my morality consists of an urge to care about others channeled through a systematization of how to help people most effectively. Someone could easily disprove specifics of the systematization by proving something like that giving charity to the poor only encourages their dependence and increases poverty. If you disproved it that way, I would accept your correction and channel my urge to care differently.

But I don't think you could disprove the urge to care itself, since it's an urge and doesn't have a truth-value.

The only thing you could do would be what someone else here suggested - prove that all other humans are NPCs without real qualia. In that case, I'd probably act selfishly when I felt like it, unless it caused too much psychological trouble to be worth it.