Iron deficiency certainly can make your PMS symptoms worse, particularly your tiredness and mood. Make sure you have an iron rich diet with plenty of legumes, soy beans, lentils, spinach, beef and turkey. in terms of your cramping, see you pharmacist for anti inflammatory medication such as Naprosyn or ibuprofen. Start this early and take it regularly for the first 2-3 days of your period to help manage the pain. If this doesn't help, you should probably see a gynaecologist.