i get it.i use to have them all the time.you should check out this guy hes helpful.i dident buy anything but i watched some of his promotional vídeos he helped me enough link
Find a set of sounds and imagens that are very soothing to you (for me its the opening of gwen stephani's what you waitong for) then focus on them. seguinte find a feel that you like, like a type of fabric and carry it around with you, then find a smell that calms you down like a candle and carry a mini with you ( I reccomend the miniatures por yankee candle company). por surrounding yourself with familiar sensations you'll calm down.
If that doesn't work try and stare at people. I know it sounds creepy but por focusing on others rather than yourself it can relieve stress.
Mark your favorito passages in a book and keep it with you so that you can read it when need.
Another weird thing, try to make música with your breathing like short short long, long short long, long long short.
