GPs don't have much of a clue about hair loss. My experience has been that if you have a good head of hair they don't even take it seriously. That's what happened with me. I had lots of hair. I lost lots of hair. I agonised over my hair loss for months but because I still had lots of hair the doctor didn't take it seriously. Go to a dermatologist. Probably not an ancient one who tells you to eat jelly beans though lol