What Causes Spotting And Lightheadedness?

Hi, I'm having some light spotting and some lightheadedness. Like, when I stand up (not fast, so it's not a head rush), I have that blacked out vision kind of effect. I've eaten a decent amount today and everything. But I also went to the doctor today, and he told me I have a, what he thinks to be, a staph infection under my arm. My blood pressure was also higher than normal, which was weird because it's usually book perfect, I even brag about it! Also, I think me and my family have been dealing with scabies (I live with my boyfriend, his son, and his father). I'm 19 years old, bout 5 foot 1 inch and about 180 lbs. Haven't had any serious medical history, not taking anything but ortho-cyclen birth control, not allergic to any medicines of any sorts, I think. Thanks for your time!