<human>: Summarize the given text in a few sentences.

So I'm already seeing a medical professional but thought I'd see what y'all thought too. 

Bio: 28 year old male, Hispanic/Caucasian, 5'11", 182lbs. Father is diabetic and mother is anemic. Luckily I'm neither right now. I'm also taking 40mg/daily celexa for anxiety/depression. 

I recently lost 50 pounds during a deployment and when I returned I had started to feel off a couple of times throughout the day. When standing up from a sitting position or from laying down, I would feel dizzy and nauseous and would have to steady myself. Then I almost passed out during a exercise session; dizzy, nauseous, narrowing vision, cold sweats. 

I went to the ER that day and blood was drawn with everything coming back normal. My blood sugar (which I thought may be the culprit) was 90 and within normal range, according to the ER doc. My heart rate though took an hour and a half to get back down to my resting hr of 80.
<bot>: Feeling like crap and I don't know if it's my heart or blood pressure or what. Thanks for the assistance!