For what it’s worth, I didn’t start seeing hair loss until I was 33. They say that by the time you notice it, it’s already decreased by 50%.
If you haven’t already done so, get on some finasteride, minoxidil, oral biotin, and derma rolling/microneedling. It’s stopped my hair loss and reversed much of it. During every cycle I lose some, but then get it back after going back to trt doses.