After I Was Diagnosed With Iron-deficient Anemia, The Doctor Prescribed

After I was diagnosed with iron-deficient anemia, the doctor prescribed 326 mg of Ferrous Sulfate 3 times daily. After I took the very first one today, I broke out in an itchy rash. I was in the hospital for 2 days this week where they already gave me 2 transfusions of iron. Isn't this too much? The doctor that described the Ferrous Sulfate is not my regular doctor, I just saw him in the hospital.