Excessive drowsiness. 75, iron in level!

I have a serious problem since more than an year now which I have no solution of. I have gone to neurosurgeon, psychiatrist, ent, etc. I feel drowsiness all day long and am not able to concentrate. Below are the symptoms I have followed by the tests I had done including blood test and mri. Symptoms: Day long Drowsiness - standing, sitting, walking, driving Fatigue Lack of concentration Memory loss A little speech problem (rare) Sleepy during driving Blurred vision Reading and Writing problen Headache mainly on both sides of the head nerve pain Understanding things take time Loss of appetite Focus lock Not refreshed after sleep even after 10hr End of the work shift after 8 hrs, i am totally exhausted. Ringing noise in left ear Test done: MRI of the brain and nerve - all clear Front sinuses MRI - all clear Neck xray - clear Blood test - all fine, hemoglobin 14.7, vitamin b12, b5 at good level, tsh 1.75, iron in level