Having nothing to hold on to can be very scary and makes you stop just right in your tracks. The trick for me is to act like a machine in order to create some kind of structure, or maybe in order to overshout the thoughts. Extreme focus on 1 dumb thing drowns everything else. You can just tell yourself that you have to spot all the red fishes and after a while you will see nothing else. It is a game I play while I am in busy, stressful rooms as well: I think of a colour or a number and then quickly run my eyes across the room and then it's like all the things of that colour just lightup and the rest gets dark and desaturated.
In highschool I used to do mathematical equations to escape from the big bowl of thoughts. These days I like to draw animals with indian ink. Trying to find the right shapes and lines and filling them in with hundreds of tiny dots. It is just like meditation, but with physical results, so even better.
It is not really 'art', but I put her with it to sort of justify the unerased pencillines and the unfinishedness of them all. I might show some more drawings like this some time.