“Thinking in pictures,” Sigmund Freud wrote, “stands nearer to unconscious processes than does thinking in words, and is unquestionably older than the latter both ontogenetically and phylogenetically.” I agree. Perhaps visual art and music are sometimes felt to be 'purer' or less reducible than literature because of this same proximity to 'unconscious processes'.
Sometimes I want to stop thinking so badly but even if I manage it for moment I'm tormented by images - also snatches of song. Anything that possesses form anchors us to the material world and perhaps this is why it can be painful. I try to visualise the insides of my eyelids when haunted by images - usually senseless ones; for instance, the top of Hampstead High Street, always looking downhill (I realised recently I usually always see a place mentally from the same vantage point), from the right side of the road, where the tube station is. But I don't want to see Hampstead High Street. So then I try to focus on the darkness and non-colour of the insides of my eyes. Or I gently press my closed eyelids and watch the kaleidescopic patterns appear and disappear.
All these are still forms, however. And I want to be without any form at all.