Ah that really *****, same thing's happening to me but I've had bloodtests and am healthy.
Make sure you're getting enough omega 3 too, that can help. Also, eat more chicken or eggs if you're not vegan. Easy protein right there.
if you fix the issue, it will likely take a month or longer for you to notice the difference in hair loss rates. i had problems with my thyroid earlier this year and went on medication to help regulate my levels and it caused my hair to fall out so quickly. it took a good 6 weeks for my hair to stop falling out once i stopped my medication again. it's not an overnight process, so you may need to wait longer to see results.
have a full blood workup done. you never know if your hair loss may by thyroid related too. it's a very common cause.