Hi there ~
I understand your concern. I should congratulate you for having beaten cancer. Iron dosage supplements are available over the counter and you should be taking it in the citrate form for easy absorption although it may be more expensive. Once a day usage is recommended. I would also recommend injections of iron intramuscularly or blood transfusion
if you blood is very very low. Consult a doctor for the same.
I hope this helps. Take care and have a lovely day!