I've not been eating a lot ever since I got anxiety. I'm still only getting two meals a day. And one of those meals is cereal. Anyway, sometimes I feel a little lightheaded? Just a little, it seems to occur more when I sit down and I'm on my computer. I didn't have side-effects when I first started taking my SSRI (Zoloft). But, I feel light headed. Could that be due to me exercising, and not getting enough food? I run 3 times everyday for about 7 minutes. I like to cut up my Cardio to make it easier.