I'm a 43 year old male and have a white coating towards the back top of my tongue, sore throat and the sensation of something being stuck in my throat. A coworker (local national) had developed very much the same symptoms around the same time. I work in the Middle East where sanitary conditions and the area cause many chances of infection. I am a heavy smoker and do drink on occasions. Don't believe I have been exposed to HIV.
It sounds like you have pharyngitis, which can be due to various bacteria or yeast. See a physician who may be able to tell more by the way it looks, and can certainly do a throat culture. HIV- as well as HIV+ people get pharyngitis.