Hiya,
I think I’ve found my twin loll…im experiencing the exact same problem as you my hair has gradually thinned over the past two years, but it seems that am the only one that notices it, I know I’ve lost a lot of thickness over the years, but when I wash it I never see any hairs lying on the bath, I have lots of bald patches and u can see a lot of scalp when my hair is in a pony tail. If your really worried about it when why don’t you go and see your doctor and he will recommend something or ask for a blood test you might be anemic, or are you stressed about something because that could be potential cause. But try not use straightening irons, blow dryers as they can damage your hair further.