Where do horrible thoughts come from?

[Unbound]

Realize they don't "come" or "go" from or to anywhere, they exist as potential configurations which may take a form or manifest within your experience according to the vibrational configuration you are currently in. Thus, as you think, you are in fact "tuning" your instrument that is yourself to many different vibrational frequencies and these in turn are represented, since the mind's eye is the observational screen of our time/space self, by the experiences of internal awareness that we commonly call "thoughts".

The Mind is turned towards time/space, the Body towards Space/Time and the Spirit merges them in the middle that they are wings that carry the Mind/Body/Spirit complex upwards in to greater frequencies of light.