I Have White Patches Inside My Mouth With Sores That

I have white patches inside my mouth with sores that are painful. Originally, the thought was that it was due to my Sjogrens Syndrome. However, very recently I was tested for Sjogrens and the results were negative. So naturally I am very alarmed. I saw my doctor yesterday and she suggested going to an ENT and having them take a culture. But now I have to wait for my health insurance to give me a referral; in the mean time, I a scared it might be something worse. My doctor said it was nothing to worry about but I can't help worrying. What do you think?
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