Postpartum Hair Loss Help!

I am 10.5 months postpartum, I stopped breastfeeding three months ago and my hair has started falling out big time. Like scary amounts of hair falling out and not just single strands, often small clumps. I’m seriously afraid I am going to have bald spots before we take our first family photos mid next month. When I ball up the hair that falls out during a shower, a single shower, it is almost golfball size. Is this normal?? Any tips to slow the hair loss?? I just went back on an estrogen birth control hoping that may help?? Any advice is appreciated, thanks.