Basically i know and use three ways to achieve this:

1) Think of something beautiful rather or look for the beauty in these thoughts (that you may or may not have recognized).

2) Build yourself a "safe space" in your own mind. This can be anything you like, but it's gotta be a safe space such that no harmful thought is allowed to enter there.

3) Do smth. haptic (finger-things, like rotating a pen with your fingers, there are many strategies there for this and really cool things you can learn by training this !), olfactoric (actively smelling, e.g. ppl. or things: "How do they actually smell?") or acoustic (play an instrument or listen to music). If you test or combine these things you basically "forget" the harmful thoughts.

No. 3) is the reason why i have almost always laying a small trumpet and an ukulele laying around in places where i am often and am allowed to do it.

For me all three strategies have their worth in it bc. you can learn to variate them in intensity as needed and can learn to combine them to get through every situation in your life that waters bad thoughts. You gotta test for yourself what works best.