I suffer social anxiety and generalised anxiety. And after benzos became no longer an option. I developed a good few methods of releiving anxiety, and burning time when my mind wasnt being very kind to me. The main thing to do is keep yourself busy, or go somehwere else. As znegative said, a walk is a good idea, walk somewhere thats roughly the amount of time you need to burn, and listen to some music, reasonably loud with some earphones. The music will sound horrible and youll want to stop listneing to it, but dont, just keep at it.
By far the best method is to learn how to dissociate on demand, I can now pretty much do it anytime anyplace. Heres me method, I sit down, and make sure there is some sort of backgorund noise (for some reason this helps a lot) like a tv, or music. I then focus intently on a single object, such as a mug on a tablea cross the room, i then mentally psoiton myself behind the mug, and imadgine what it looks like from the otherside, then waht it looks like inside, then I imadgine the texture of the ceramic if it where broken, the shine of the glaze and the colour of the tea stains inside.
The idea is basically to focus intnetly on things you cant see, so have to imadgine. (much easier when related to real world objects, like a mug you can see).
The next hard bit is staying dissociated, like learning how to lucid dream, you have to learn to stay awake enough that you realise you are dissociated, adn want to stay that way. But not so awake that you "snap" back to the real world. Techniques like these allow me to have a job, some sort of social life, and generally leave my house without persistant panic attacks, it sounds ridiculous, but trust me it works. When benzos arent an option anymore, then neccesity negates logic, and you learn something new.
Kinda %) right now so sorry if that lacks sense.