I'm voting for mild schizophrenia spectrum disorder (maybe rapid cycling schizoaffective bipolar?). Psychoactive drugs can trigger schizophrenia in some people. Due to the nature of the intrusive thoughts, I would also put a vote in for mild-moderate obsessive compulsive disorder. I would not say ADD/ADHD because of your apathy, but instead you are disconnected and unmotivated because of said intrusive thoughts. If you get those under control, I think that you should get better in the motivation department. May I ask what a heavy dose of ecstasy is, and also what your history with psychiatric medication is?

Please understand that in schizophrenia you don't have to believe what you are hearing.