O.L.
Are you sure it's an abnormal amount of hair loss? I'd guess that I lose about 20-30 hairs when I comb my fingers through my hair after showering. (I have curly hair so I don't use a hairbrush.) That doesn't count what I lose here & there over the course of a day, or what I lose while actually in the shower.
Sometimes if you've gone through a period of low hair loss (like after being pregnant & having a baby) it can seem like you're suddenly losing crazy amounts of hair when it's really the norm... you've just gotten used to it not happening.
Maybe you could take in the hairs from one day and ask the doctor or pharmacist if that's a normal amount of hair to lose after brushing or not.
Best of luck!