Hair falling out?

My hair is constantly shedding little broken pieces of hair everytime I brush it, but lately I’ve been noticing if I run my hands through my hair - as if I’m putting my hair up in a pony or washing shampoo out.. my hair is coming out! It doesn’t feel or sound like it’s ripping. It just comes out anytime I grab my hair... some strands are thick too like pieces of hair! Why is my hair falling out should I be worried?!? And what to do to stop this. I don’t want to be left with no hair 😫 at the rate it’s going. I might be