I have hairfall. Please help. Grow back!

I had severe hairfall in month of jan like almost more than 1000 strands of hair must have come off after hairwash. I was preparing for exams and had a major exam 3 months ago so i thought it was stress. The hairfall continued till month of February but it was like 200 strands a day. By the month of march Hairfall haf reduced to less than 100 strands a day. My crown area has become scanty and my scalp is starting to show in the forefront. Its been 6 months but those hair dont seem to grow back just the hairfall has reduced and is consistent. I generally have thick straight hair now only 1/4th of my hair is on my head. I have not faced hairfall like this before.Suggest me some medication.I started using complete chemical free shampoo and hair oil. I took biotin and IFA for 2 months.Took multivitamin and cal d3.Suggest me medication nd solution nd tell me what investigations i should take.I cant take a chance for one more shedding like this I will be bald. Why is the lost hair grow back