Don't run, but briskly walk to find another doctor....sorry for the bad humor, but the way some doctors work really gripes my ***. You obviously have a health care need, the least he/she could do, would be to tell you what it is that you are being treated for! I would definately try to find myself another doc - as others have suggested, I would try to see an ENT. Good luck.
See an ent possibly viral antibiotics will not respond that well to a virus and that you have cankre sores sounds like a virus try gargling with warm water with a tablespoon of table salt 3 or 4 times a day it sounds painful but really does help clean out your glands and your sores try tylenol for the pain watch your diet stay away from acid foods such as oj and tomatoes try eating yogurt to balance the good bacteria in your mouth. Hope this helps.
I strongly suggest to go to another doctor - get to an ENT (ear, nose and throat specialist) if you can. If your GP won't refer you, go to another GP or try to get an ENT app directly.
Good luck!