The meaning we give things can affect healing from them, so is there an alternative meaning you can give it that frames it as part of your personal Hero’s Journey instead of a “bad thing that happened”?
As long as we feel owed (however right, and however utterly valid) healing is impossible. Things recur in the mind because they want resolution, they want a meaning that allows them to become Past = Passed, instead of still on our mental “to do” list as needing restitution.
The Hero’s Journey concept isn’t about letting go in some weak way like your suffering didn’t matter, it acknowledges the scars, the battle, the barely-holding-on part, that there ARE real monsters but they CAN really be slain, no matter how odious and unjust they were. In fact their disgusting qualities attest to your own power.