He's doubting it now because part of him thinks Hermione spoke the truth about his personas being a sickness

Well, multiple personalities sure can be, eh? I suppose that both he and Hermione grew up in the Muggle world, so it might be just that much more strange and, dare I say, undesirable when taken from that point of view. Poor thing. Part of me just wants to make it all better, while another part of me wants to see him totally self-destruct, and Draco be the one who pulls him back together with acceptance and love.
/fluff-fest

:O)