Im sorry that your having a tough time

I deal with very similar intrusive thoughts that can be very disturbing and inappropriate.

Unfortunately I have yet to figure out how to stop having them.

I know personally they happen more frequent when I am under high(er) amounts of stress or when there is a specific issue or conflict going on.

I agree with everyone's suggestion and try and seek some professional help.

In the meantime keep reminding yourself that you are not your thoughts! It isnt a choice and you know you dont want to do those things!

Its a struggle that I can very much relate to. Staying busy helps but it has to be mindful.
I try to say something similar to myself like, go away ugly thoughts, or even shut up.
Staying mentally engaged also helps.

Hang in there.