My Daughter (3) Has Thrush On Her Tongues And Was

My daughter (3) has thrush on her tongues and was prescribed daktarin but she also has ulcers including a very large sore one on the tip of her to tongue. She's in a lot of pain taking the medication as it stings her ulcers. She hasn't eaten since Thursday although I am managing to keep up her fluids. Is there're anything to ease the pain of the ulcers? Is there an alternative to daktarin?