Why am i losing so much hair?

I am a 14 yr old girl. Within the last month or so i noticed im loosing a lot of hair. I naturally have very thick hair so it's not like im going bald but still... Is there something wrong with me? every time i shower i pull out tons of hair, then when i brush my hair tons comes out. when i do laundry theres of hair that get tangled up in my clothes. i need to empty my hair brush very often. this has been happening for maybe a year now but i noticed that theres been a lot more hair coming out. i havent had any diet changes recently.. i just want to make sure that theres nothing severly wrong with me.. thanks for your help!