the symptoms you're having - white or yellowish layer on your mouth roof and/ or tongue, alongside with tonsils that sound like they’re inflamed, from what you described - definitely do sound more like they are caused by yeast infection. In some cases bacterial infection can cause similar symptoms, but they are usually more focused on tonsils. These symptoms are highly unlikely to be related to AIDS, if you know you're not HIV positive or have been engaged in risky sexual interaction. Did your doctor prescribe you anti-fungal treatment? I'd recommend you to complete the full course of medications your doctor prescribes - chances are that will be all it takes to get cured. And if you suspect you might be infected with HIV, than the easiest way to not have to worry about it is to take a test.
Wish you all the best,