after sex i very suddenly became light headed, spinning out and dizzy and had to sit down. also had intense lower abdominal pressure and pain/discomfort (during and after sex) and constipated feeling (small possibility of being due to slightly changed eating habits past couple of days). also had a light sweat and felt very hot, but 10 minutes later after it subsided i became very cold and clammy...? i used to get dizzy spells due to low blood pressure but this one lasted about 10 minutes and was much worse.