I have the most brittle nails!! 😩😡

When I was in high school I was diagnosed with anemia, my doctor said it was because I didn't have enough iron in my diet so I do my best to eat iron rich foods (I don't like iron supplements, side effects aren't worth it). A few years later I was in the hospital in Greece because of salmonella and they informed me I was still suffering from chronic anemia. That was 2013 and I haven't been tested again since. My anemia doesn't normally affect me however, my nails SUCK. They never get long because they're weak and brittle and break very easily. Just now, I was pulling my bra down over my shirt and I bent my thumbnail back, just from that! It's so painful and I'm really fed up! I've been taking biotin for a few weeks and so far haven't noticed a change. Anyone have tips?!