Hair loss due to deficiencies?

ok so, ive been straightening my hair since i was 15 (now 19) i recently stopped late last yr since i found out i have several mineral deficiencies and mainly with iron. my hair has really thinned out. my head loooked like a fro prior to me losing my hair at a very fast rate. now im panicing and totally regreting straightening my hair for so long cause with the anemia..its just gotten worse. my question is ..the strands of hair that i lose..ive notice it has a tiny white tip like aball on it. does that mean its come out of the root and wont regrow or is that little white tip supposed to be there with normal loss? and how do i stopped this madness ..if i patiently wiat and my deficiencies are restored will my hair return to its original thickness?? cause at the moment my hair line has reallyyy thinned out! and new hair isnt coming back