What Causes Drowsiness When Having Low BP?

I am a man of 45 years old. My pressure remains always low (100/70). Blood sugar empty stomach 4.0-4.5 and after meal 2 hrs later is 5.0-6.0. Tendency is hypo(both for blood pressure and blood sugar). My total cholesterol is 215 LDL and HDL is under the reference range . Recently feeling drowsy, hungry meal after 3 hr. what should I do now?