Why am i losing so much hair?

I am a 16 year old female and for the past few months I have lost a lot of hair. I used to have very thick hair ever since I was little but now it's really dry and it's thinning a lot. Should I be worried about this? What could be causing it? I used to take the birth control Ocella but i switched because it caused a lot of problems for me so now I am taking Tri Lo Sprintec. My hair loss/thinning started before I changed birth controls and it hasn't gotten any better. every time I run my fingers through my hair tons of hair just comes out like I'm shedding or something.Why am i losing so much hair?
i get that to its a common symptom of PCOS polycystic ovarian syndrome that can cause loss of hair and malnourishment can cause it as well, im not saying you have either of those things but i would recommend seeing a physician about itWhy am i losing so much hair?
this just started happening to me also. it especially happens to me when i am in the shower and shampooing or conditioning. i was at the point that i was scared i had a disease or something. i asked my doctor about it and she said that it is most likely something caused by stress. the trigger or cause of stress can go back from last week to as far back as three months ago. another reason is because your eating/ sleeping patterns might have changed. i dont think it has anything to do with your birth control so dont worry. hope it helps (: