Male 20 yrs old A lot of thinning on top of head, hair falling out in shower

Im 20, male, and have noticed that my hair is so thin on the top of my head.I have thin hair to begin with. The scalp is visible across the whole area. Also my hair is falling out, i get a handfull every time i run my hands through it in the shower. One or two fall out when my hair is dry and i run my hand through it. My dad has a full head of hair at 50. His dad had a full head of hair. My mom has extremely thin hair and her scalp is starting to show through, however her dad had a full head of hair. I have no uncles. What are my options?

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