Dental Abscess

Just wanted some advice really. Have been getting recurrent single small blister like white spots on my soft palate for quite a while. They give me the feeling that something is stuck in my throat and if I pop them, I get sore throat, neck and ear pain. They last a few weeks then go only to recur later. I have been tested for mono and thyroid - all negative and my doctor has said I am fine. During the last episode, I found a small painless lump on my gum behind my last molar. The dentist said it was an abscess and I have since had 14 days of antibiotics and a root canal on a nearby tooth. The swelling has kept discharging and refilling since then and I have had several of these blisters/spots. I have noticed that they all seem to occur with a cm of this abscess. I also have a small painful lump about 1 - 2 inches below my ear. Could this be a swollen gland and could these spots be due to this abscess/infection? Obviously I am concerned I have cancer but my doctor says the feeling of something stuck in my throat would be continuous not intermittant. Any ideas anyone?