Your brain is lying to you. Part of that comes naturally to it, part of it is surely from being damaged by the past poison. You need to find a part of you that can see above the clouds a little here, that can imagine a little more than you can even imagine you can imagine, so to speak.
You're fighting for your life here and need to be willing to do whatever's necessary to get off the poison. That will include giving up old ideas about who you thought you were, and that's doable but takes some time and patiently applied effort.