Oh, I am SOOO sorry you are going through all of this. Sometimes life throws you for a major loop and all hell breaks out emotionally and physically. I sympathize with you.
I had the same issues that you are describing. Even if it doesn't test positive for yeast, I truly believe that it could in fact be that. A swab will test negative if it's on the outside of your body. That was MY own case!
I have been prescribed four different lotions (and potions, ha!) to get rid the stuff I had recently. I swear I felt like such a head case constantly going in and out of the gyno's office. (What must they think of me??? Yeah, those were my thoughts).
Things to try:
*Change your laundry detergent to something gentle like All Free & Clear (even if you don't think it's that). Change your soap to Dove Unscented. I was stupid and using Dial which is an antibacterial soap. It only aggrivated the area more!
*Go panty-less whenever you can. No one will know but you if you do it descreetly of course.
*If it's tight, DON'T wear it!
*Only cotton underwear.
*Be careful about how you bathe - not too frequently and avoid soap directly to the vulva. When drying, use a hair dryer to absorb any extra moisture.
*Try apple cider vinegar or baking soda in a tub.
*DO NOT touch the area if you can help it. Everytime you look at it (spreading yourself open to examine it, like I did) or scratch it, it has to heal all over again. My gynocologist stressed this to the max.
*Find a good cream that works and keep going back until you get it fixed. Don't let anyone make you think it's in your head, because you know what's normal and what's not.
*Eat plain yogurt or take an acidophilus supplument daily.
It sounds like a thrush to me. I would imagine that they tested you for things like this and bacteral vaginosis, but sometimes the little buggers will still remain. I took 2 diflucans before testing POSITIVE for yeast! The damn pills did nothing for me!
The thing that has worked best for me is nystatin and triamcinolone acetonide cream. I believe it's an antifungal and cortisone. Helped tremendously! There is another lotion called Clindesse that helped me once before 3 years ago.
Remember that it sometimes takes trial and error, but you will NOT be like this forever! Think of anything and everything that could be affecting it and modify as needed (new condoms, different lubrications used in sex, boyfriend's soap/cologne, etc).
Good luck and don't let it consume you!!!