Dry mouth. Sore throat and red spot on roof of mouth "IMAGE"

Had this for past 3 days now mouth feels dry and sore, roof of mouth feels very irritated, any idea what could be going on. I notice today I keep getting loads of flehm up from back of throat also I have to wait till Monday to send form in to doctors and even then its takes for ever to hear back so in mean time I wondered if anyone had any ideas and how I could help my self .