I've had the same problem, I wasn't sure whether it was hormone related or because I had incredibly low ferritin levels - it was completely depleted at one point. I think it might be worth having your levels checked. It needs to be higher than within range, optimal ferritin levels need to be at least 80 to stop hair loss and above 100 to encourage hair growth apparently.
I've struggled to raise my levels, even with iron tablets, it took months, years even, now it is at the highest about 50. I use plantur shampoo which seemed to help reduce the loss and give my hair a chance to grow back a little, then I started HRT for low mood and anxiety, within a few weeks my hair started shedding again. So maybe in my case it was a little bit of both hormones and ferritin. But I think that having your ferritin levels checked is really worth it.
Have you had your hormone and thyroid functions checked?