Weakness, Tiredness and Sleepiness.

Facing constant tiredness and Sleepiness throughout the day despite of having complete 7-8 hrs sleep at night. Unable to concentrate for long and feeling weakness most time of the day. Not suffering from cold or fever but feel tired. I also do walking atleast 30 min almost everyday. I am occasionally consume pain killers for headache or body ache along with antacid for gaiters issues sometimes. My diet is mostly home food. I've tried having protinex in my morning milk and shakeferol in the evening, though followed only when feeling tired and weak. I'm a vegetarian. Whenever I'm trying to think consciously I feel tired and sleepy. I tried taking revital tabs and iron supplements for a few days but it didn't help for long time also I get acidity having these tabs so I stopped. I try to take a nap but it doesn't help. I always wake up tired and sleepy. Please assist as i need my daily energy levels and stamina back. Thanks.