Really tough and rough OP.
Things people have found helpful:
Imagine each thought is in a bubble - burst each one.
Name the person they're coming from in your mind. Women find naming them a man's name helpful. 'Shut up Gary', each time you have a thought.
You really aren't a psychopath. A psychopath doesn't worry they're a psychopath.
Meditation. Cultivating the witness. Who is the I that sees the thoughts?
Perfectionism? There's an underlying perfectionism. Like, you have a thought,ok, great, nobody is perfect with perfect thoughts. Thoughts can be wild without meaning anything.
Highly recommend books about it or finding a therapist that specialises.
Sometimes it's not the thought. What's underneath the though You think about having sex with your father/brother or whoever. Like, is separation an issue. Do you need more freedom? Less enmeshment. Look beyond the obvious meaning: it's not about sex with your brother/father etc.
Guilt and punishment. Really depends on the context. Guilt for striking out on your own - mind produces punishable thoughts to stop you. Underlying conflict.