Feeling tired, worse with an ongoing headache for the past couple of weeks. lightheaded even while laying down. sweating or just hot, blurry vision?

Blurry vision?: Go see your eye doctor! If my vision changed, I wouldn't wait another second wondering why. As for other symptoms, may simply be due to dehydration from heat/sweating. Try consuming enough water to make urine pale & clear. If that's not enough to make you feel better, it's time to see your Family Doc.But in mean time, go see Ophthalmologist or Optometrist (whoever you can get appt with first).