I Was Told I Had Scabbies Which Freaked Me Completely

I was told I had scabbies which freaked me completely out I won't go through that but a Dermatologist said oh honey your in pain after seeing my mouth well she gave me a sample and so little it was two use it worked she said my insurance won't pay and it expensive I have Lichen Planus I'm in pain in my mouth mostly but it's all over with severe itching along with the pain I need RX cream I tried 200.00 in over counter stuff please what can I ask them to pricribe? And what do u think the sample was and a price? Thank you please help