And talking about the intrusive thoughts with someone or a psychiatrist can also help... I just got rid of some weird thoughts about food and people by talking about it... The food thoughts were like very weird nonsense thoughts about just saying things like "Mira's Haggis" for example. LOL.
Talking to others might help to get understanding and if you learn something is nonsense you won't think about it because you won't believe it anymore, but to get rid of the type of negative thoughts you have saying and believing "All my thoughts and emotions are washed in the blood of Jesus" will help you best.