There is a big difference between having anxiety about something and the thing itself. Your anxiety can go away without the thing you are worrying about going away or not. So it doesn't matter whether or not something goes away, you can still lessen your anxiety about it.
There are major differences between attempting to forcefully stop thinking about something, and accepting that you're thinking about something and then able to move on to something else.
In the first case, you're working against your brain, and getting it to behave is more likely to require some kind of violence and cause some sort of damage.
The other way, where you accept and then can move on, is more like moving with your brain.
Instead of trying to stop the river, you redirect it.