I am loosing my hair badly..............

Hello,My name is Erum (female) and I am 27 years old. I had very nice long hair, they are wavey and thin but they were not falling. Now for the last 7 to 8 months they have began falling, some time I see dandruf also. I use to oil my hair once a week but some times I feel itching on my sculp and if I apply oil again I feel comfertable.I shampoo and condition them twice a week, but there is no improvement. I don't even dye or use any other chemicals neither do I am taking any drugs to prevent this hair loss.I had some mensturation problem, so I did a three months harmonal course, and I observed that after having those medicens this problem is increased.So please help me in this matter, I like long hair and I want my hair back as they were before.Thank you,Erum.