To replace the mucus down there, you might try taking Siberian Eleuthero root from the health food store. (Ginseng) It helps you make your own estrogen. (Also good for osteo).
Wishing you the best
This area probably needs to be biopsied. There are a number of chronic skin conditions that can affect the vagina (like lichen planus). Good luck with it.
I did go to doc last night and told me having a bad reaction to hot peppers or hot food plus antihistamine plus liners .... Now cannot wear under wear for 3 weeks, no gym, sit baths, stop all pills for itchy and wash clothes and rinse 2 times.... Very possible all this cause this bad itchy..what has happen it remove my own mucous down there and made me feel terrible :(
I would definately see a dermatoligist. He/She may need to biopsy an affected area to determine any possible pathogens or abnormal cells which could be suggestive of some kind of inflammatory condition.
While waiting to see dermatology, I recommend refraining from douching, use very mild soap and water when bathing in that area - steer clear from the scented stuff. Stick with pads during menses that are not scented and make sure you are wearing cotton underwear. The silky and other fabrics tend to "hold in moisture" that can irritate. Additionally, change detergent to 'free and clear' I'm surprised GYN didn't at least attempt a round of diflucan.