Ferritin dropped by 8 in a month

Hey(im 20f), in march i took a ferritin test and found out i had low ferritin level, (i probably had it for a long time since i had odd cravings for years whatever they call Pica or something and immediately disappeared after i started taking iron supplements ). I started taking iron supplements and in 2months it got higher by 3, so i continued taking it until august, cause my doctor recommended to stop taking it a month before taking a test again. I took a test few days ago and now my ferritin level is dropped by 8which is way way under norm, how is that normal or even possible in a month? I don’t usually worry about it but about 2 weeks ago i had really bad dizziness and anxiety. whenever i stood up, i was out of breath, it was even hard for me to move and i felt like passing out but finally threw up and got better. Later i realized it was because of the low ferritin cause Since then i noticed that my anxiety level is high to the point that sometimes i find it difficult to breathe. Is there anything i can do except taking iron medication?