What can I do to stop a receding hair line? 18 years old. (photos)

A month ago my salonist told me my hairline was receding and I thought no it couldn't be. I've seen a Derm but he didn't act worried. I have noticed my hair has gotten really thin over the last 8 months but I thought because of the way I prepare my hair. I've notice more of my hair falling out in the shower and my scalp itches pretty bad. I've always had long thick hair. My dad is bald but no one else in my family is out of ten other siblings. I do have very high stress because of mental disorder