Thanks for the info! I don't know why the doc didn't mention this to me when I went in. I also found some info online, so if anyone else wants to know more about the card, check this out:
http://www.patient.co.uk/showdoc/23069022/Who can get a prescription exemption certificate?People who have certain medical conditions
Although there are many conditions requiring permanent medication, only the following qualify for an exemption certificate:
A permanent fistula requiring dressing.
Forms of hypoadrenalism, such as Addison's Disease.
Diabetes insipidus and other forms of hypopituitarism.
Diabetes mellitus except where treatment is by diet alone.
Hypoparathyroidism.
Myasthenia gravis.
Myxoedema (underactive thyroid) or other conditions where supplemental thyroid hormone is necessary.
Epilepsy requiring continuous anti-convulsive therapy.
If, because of a permanent disability, you cannot leave the house without help.
If you have one of these conditions,
get form FP92A from your doctor's surgery and fill it in. This is sent to the Prescription Pricing Authority who will issue a Medical Exemption Certificate.