Yesterday morning i was doing my regular routine and all of a sudden, became nauseous, sweaty hot, dizzy then fainted. I came to after needing help up off floor. Didn't faint again, but the rest of the day n night, and today, my legs and knees are week and hurt. Ive felt dizzy a little a few times today, but nothing like yesterday. Is the legs/knee thing from falling or should i go to ER just to be safe?