I have read that although unsightly, a white tongue is usually a temporary, harmless condition.
Yes, it is possible for either partner to become infected with HIV through performing or receiving oral sex. There have been a few cases of HIV transmission from performing oral sex on a person infected with HIV. While no one knows exactly what the degree of risk is, evidence suggests that the risk is less than that of unprotected anal or vaginal sex.
You will be alright and please protect yourself for oral sex since it is worrying you. I commend you on taking measures to wear a condom otherwise.
All the best
Muthoni (Mson)