I'm 16 and my hair is falling apart!!?

I understand that we shed 100 strands of hair or a little more a day..but im loosing a lot more! like i ran my fingers through my ahir and a fairly good sized chunk came out and it wasn't tangled or anything..im not pregnant or on birth control..and I'm just wondering what could cause this. I workout every day and eat a healthy diet and so im just wondering what i can do to stop it..and the hair isn't broken the follicle is still attached..thanks for reading this and any help would be greatly appreciated!