I wonder if something like exercises for the concept of psychological flexibility could help. In reality we're all equally important, as we are one - so within this context, your belief isn't wrong. The important part then becomes in how you treat yourself and other people, being kind, and practicing non-violence (towards yourself and others). I wonder if any shamanic traditions like Ayahuasca ceremonies or one more potent like Iboga could be beneficial of "flushing the brain out" as a sort of ego mind reset, dissolution. I haven't looked into or nor had personal benefit or experience related to a Delusional Dis-order, however if you feel called to it, you can find organizers or shamans to see if ceremony would be safe for you; you can't be on certain medications as it wouldn't make the ceremony safe, though some shamans have different requirements or understand than others.