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 video he helped me enough link
Find a set of sounds and gambar that are very soothing to anda (for me its the opening of gwen stephani's what anda waitong for) then focus on them. selanjutnya find a feel that anda like, like a type of fabric and carry it around with you, then find a smell that calms anda down like a candle and carry a mini with anda ( I reccomend the miniatures oleh yankee candle company). oleh 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 oleh focusing on others rather than yourself it can relieve stress.
Mark your favorit passages in a book and keep it with anda so that anda can read it when need.
Another weird thing, try to make musik with your breathing like short short long, long short long, long long short.
