20 Year old and Dont know what i Have

[Vince1234]

Hey Just wanting some direction on what Kind of thinning or hairloss i have.
The Hairloss started at the beginning of the year around march (6-7Months ago)
i saw a bit of hairloss/thinning on my hairline and top of my head but nothing on the crown that i noticed.I have had very stressful semesters in 2017

fast forward to now where i Clearly see thinning on top of the head, Slight receding hairline and crown. Keep in mind i had always had a somewhat Big bald crown. I dont know if i am stressing out for no reason or if i should be genuinely concerned.

All these photos were taken recently

My dad is in his 50s and just started thinning on top of his head