There's no one trick suits all sadly.

It depends what the negative or intrusive thoughts are, why they started, if you can negotiate with yourself and genuinely realise the reason they're happening due to things out of your control.

Sometimes the thoughts can be OCD based, or more of a learned behaviour, that's why it's best to speak to a psychologist.

Research one that's got a history and good reviews and If you can, try that.

You can get some terrible psychologists, but eventually you'll find one that understands.

Wishing you all the best