I'm probably only telling you things you already know, but the baby shampoo might still be causing you problems. The pH of your vagina is finely balanced. At a normal pH, the acidity is too high for the fungus candida albicaans to flourish. Any kind of soap agent (including the shampoo) decreases the acidity of your vagina and inside your vulva and the yeast grow like crazy. This is what a yeast infection is and you know all the symptoms from there I'm sure! I used to shave down there, and even the diluted soap suds that would wash in was enough to give me a string of yeast infections till I had seen a doctor who could give me heads up on what was going on. Other things like antibiotics are obviously going to increase your risk of thursh. Maybe give the baby shampoo a miss for a while and see if that helps? Many women just rinse with water and don't find any irritation.
I have been having the same probably for almost a year now...except mine comes back about every 2 weeks or so. The doctor thought it was the birth control pill (I was on it for 7 yrs (and was fine)...went off for 2 yrs...and am now back on it)...he changed my pills and gave me a months worth of diflucan to get it out of my system. This was in August...they came back within a couple of weeks of taking the last diflucan pill. Please let me know if you find anything out. I don't have health insurance and every time I go to the Dr.'s I spend about $200 or more just to get another infection within a couple of weeks. It's frustrating!!!