Asked about my mouth sore that started as a cluster of blisters. told me it was angular cheilitis, put a shot of cortisone in it. not getting better?

Depends: Angular cheilitis is usually a yeast infection at the angles of the mouth and clears with antiyeast cream. Blisters are usually herpes virus which tends to affect the lining of the mouth on the gums, lips and hard palate. It may take several weeks for them to heal. Aphthous ulcers don't start as blisters but as shallow ulcers usually on the palate, cheeks and tongue that clear in 7-10 days.