you said he used to try to understand but lately has been short with you.. this isn't really your problem, it may be difficult to accept that he isn't motivated to help you as a partner. or maybe he doesn't understand and has given up on trying to understand.. but if i were you i would try the following; carry a little notepad and pen around with you and when you have an episode i would make a log of it. note everything you can, time, date, your current mood whether it be happy/sad/depressed/surprised/anxious/hopeless/frustrated, what may have trigged the episode and maybe even what your boyfriend can do to help in that specific situation. at the end of the day when he gets home from work or whenever you guys are in bed before going to sleep share these notes with him.
i think this may help him better understand what you go through on a daily basis and how intense these thoughts and feelings are for you. it will even give him insight on what he can do as a boyfriend to help you through different situations. of course, i'm assuming he'd be willing to do this for his partner.

again, this is something i would try myself... just sharing my personal point of view and i hope it helps. good luck!