I agree it sounds like a yeast infection also known as thrush but if you haven't had it before going to seeing a doctor or sexual health clinic maybe a good idea. You could also visit a local pharmacy for advice there are many products available and they are trained to look into medical interactions etc.
These such matters actually we're the topic of conversation at a girls night I went to awhile back and one friend said that if she wears anything other than cotton underwear she's guaranteed to get a yeast infection the same applies with for another friend but she also said thongs or g string style undies are a no go too. They also recommend that when you have one you should cut down on the amount of sugar you eat someone did explain why but I have forgotten. But the biggest thing to remember is that it's a very common problem which anyone including men can get an it's nothing to be embarrassed about