Pimple type lump in roof of mouth.

I am having an habbit of eating hot food and tea , 3 months back i drank a very hot coffee and the next day i noticed sore roof of mouth and a rounded pimple type hard swelling on my roof of mouth , no ulcer and no pain in the swelling , In the morning when i wake up it feels a little flat , after i eat something it becomes more prominent it feels very smooth to touch and hard round mass. When i press it hard it squeezes and area turns little purple , but since 3 months its not improving although its also not increasing in size i can feel 2-3 more similar type of round hard lumps adjacent to this but those are very small to feel and touch but the are feels very smooth to touch , I have never smoked or taken any tobacoo . I am really afraid of thing being cancer.