I've had low iron in the past for decades. One time i had to have 2 blood transfusions in a single weekend. So thank you for donating blood.  Anyhow, i may be able to help. In my experience, the pills do nothing. I took them for 6 years and was still anaemic. You may have  s malabsorption problem. If you take vit c with the iron, it aids absorption. You could also take digestive enzymes with your food to help you pull iron out of food.   Also bear in mind that iron impedes absorption of other things, so don't take the pills at the same time as anything else.   Anyway, what finally worked for me was an iron infusion. I only needed the one (2012) and have been replete since then (and i don't even eat meat).  I don't know how easy it will be for you to get one, but it's worth it. Next best thing is an iron injection. I've had them too and I would avoid them unless necessary because they have to be IM injections, which are done with a giant needle plunged deep into the muscle. If not administered correctly, the iron can stain your skin permanently at the injection site. Also, you will need several of them. So i hope you can get an iron infusion. Low iron in women causes a myriad of other problems, so I hope you can address the issue. IMO opinion, the expense of a one-off iron infusion will be worth it.