M.M.
Hello J.,
Although my daughter has never had a yeast infection, she's had terrible diaper rashes before. My cousin recommended Dr. Smith's diaper rash cream. She used it with her daughter (she had a diaper rash so bad that it was almost like an open sore- oozing and a little bleeding). Anyway, she told me to really put ALOT of it on (she compared it to putting it on as thick as icing on a cake). Within just a few days the diaper rash was gone...I couldn't believe it!
Also, using soft, baby wash cloths might be a little more gentle. Not sure what soap you are using, but I would make sure it is fragrance free (or maybe skip using the soap for now and just use several clean wash cloths and water during each diaper change). In addition, letting things "air out" also helps. I used to lay my daughter on the floor under a few towels and let her "air out" with no diaper on for at least 10 minutes after each diaper change.
Hope this info helps!