Am I Balding?

[FrodoBaggins]

Im 20 years old and in college, have been under extreme stress and many sleepless nights. Noticed my hair has started to thin and wasn't sure if this was because of hereditary balding (my Dad and Mom both had tons of hair until there 40s, so did my grandparents, but not my grandmas brother.) Would appreciate some insight as to what it could be!