I haven't had any of those problems with my Sjogren's, just the severe dryness. But, I remember thinking I had yeast infections for 2 years. Turned out it was just dryness. No infection. Do you have the funky vaginal discharge? Or is it just raw. The discharge is what tells you it is definitely an infection. Without that, it is just a rawness from being so dry. Anyway, eat a yogurt at least once a day. That helps to balance things and actually helps yeast infections. And, see a rheumatologist!!! You may need an immunosuppressant!
You may be experiencing some immune dysfunction. Infections are commonly seen in immune dysfunction & autoimmune patients. With CFS, I used to also frequently get yeast infections and have the yellow tongue. The only thing that helped me (believe it or not) was a chinese herbal product.
Nystatin is yellow to begin with, so that is the reason for having yellow tongue....but do you have any tiny hairs on your tongue?, if you that is good,that means no yeast infection... you just now may be dealing with dry mouth.