Talk to Dermatologist on Hair Problem

I am 20 years old and facing severe hair loss. Earlier my hair were quite good and thick, even though I had some baldness. I shaved my head, but after that my hair didn't grow back like before. Now I'm almost bald.

The hair that are growing now are extremely thin, like baby hair. I don’t understand why this happened. No one from my father's side of the family is bald. From my maternal side, only 1 or 2 people are bald, rest all have full hair.

Can my hair grow back naturally? Will medicines like Minoxidil/Finasteride work for me? Or is a hair transplant the only option left? Please suggest.