I am 46 years old, went through breast cancer surgery and treatment one year ago (chemo), did not have periods for a year following the treatment up until May of this year and when I started my periods again I have been getting episodes of very brief panic feelings (3-4 seconds), I vomit then faint and when I awake I need to sleep. Each episode has 5-6 of these bouts of panic, vomitting and fainting then needing to sleep and the whole ordeal lasts for approx. 7 hours (during which I have to sleep). Afterwards I feel a little 'hungover' (kind of fuzzy-feeling) but otherwise able to function pretty normally. This happens around the same date of every month even though my periods are not consistent. Have had blood work and CT scan and both were normal. Any suggestions would be greatly appreciated!