I'm happy to report that after more than a month of treatment, I appear to be thrush-free.
Fortunately, Oscar's symptoms cleared up after a day of treatment (Nystatin), back on May 13. I started Diflucan the same day (pills). After two weeks and no change in my symptoms, I started an increased dosage, plus Nystatin topically four times a day. Early on, I also started taking acidophilus and Vitamin B6, both recommended by the midwives, and using a vinegar rinse on my breasts after each feeding/pumping, recommended by Mary at the breast feeding support group I attend weekly in Silverton.
Finally, I can say that breast feeding no longer causes me pain and anxiety. I don't have the intermittent deep tissue pain nearly as frequently as I'd been having it and my nipples aren't plagued by the constant (when not nursing) pins-and-needles/burning/stinging sensation.
Whew. It was a very long haul and not without tears and frustration. One of the things that saved us (I say us because this affected Adam and Oscar, too) is the B.A.B.I.E.S. Clinic in Silverton (affiliated with Silverton Hospital). The support, encouragement and information we received there was a life-saver. Of course, another thing that got me through this is Adam's support and encouragement.
Up next: introducing the bottle to the little man.