Feeling weakness and sleepiness always.

Hello, I am shivam abd 18 years old. A month ago i went to my village where some people made me drink some water ubder the name of some baba due to which i vomit there abd since then i am having problems. I always feels tired and weakness and sleepiness in my body. Also there is constant headache which sometimes becomes unbearable. My blood tests : Cbc, TSH, liver, kidney and electrolytes ( sodium and potassium) are all normal Also, My stool and urine test is also normal. Doctor prescribed me some medication for IBS but i am having no effect. Please tell what could it be. Before i drink that water everything was fine. Is there any chance of worms if ges then why are not appearing in my stools. I am confused what is causing this problem witg my body.