I Have Type 2 Diabetes. My DR Had Me On

I have type 2 Diabetes. My DR had me on a high blood pressure drug called Atenonel. A couple months ago she changed me to Lisinopril. After approx. 2-3 weeks, I noticed the inside of my lips was swollen. The tip of my tongue felt like it had be burned by something hot. Dr told me to stop the Lisinopril to see if swelling went away. It has been over a month now and the swelling has not gone away. I have an appointment scheduled in a couple weeks. If not an allergy to the med, what else could cause this symptom?