I went undiagnosed for 5 yrs seeing 6 Urologists that actually made things worse. Vitamin C, Cranberry Juice put me through the roof in pain and brought on the Urinary Tract symptoms but negative UTI's. I also noticed that if I had orange soda, coffee, or chocolate it set it off too. I finally met a Urologist fresh out of school with new remedies and a clear understanding of what was going on. She said I needed to have a Potassium test. This is where they put a catheter in you bladder and inject a potassium solution. There are 3 levels and each level they put in has a stronger potassium strength. The test was tried on me and by the start of the second injection I about flew off the table. It was positive I had IC. I started a long journey from that day learning how to put a catheter up my Urethra and make the mixture given by the doctor to inject into my bladder. I started 3 times a day and saw results, I went to once a day then 3 times a week, and then once a week to 3 times a month and then maybe once a month to once every other month and then now eventually after 7 yrs later I have 1 or 2 episodes a yr. You can take the capsules (Elmiron 100 mg) and not inject them into your bladder, but it is a better way of medicatiing the area that needs it, the bladder. I went on a very strict diet for 1 yr and was doing excellent to the point it was as if I had no problem anymore. Unfortunantly I got too comfortable with the results and lazy. I am almost back to the same state I started in , not good. I highly suggest you get tested for IC with the potassium testing and then if it is IC learn all you can about it. Go on a strict diet, which is not fun, but if it is getting your life back you want it will do it. It might take about a year, but its worth it and remember if you don't keep to it you can end up right back where you started. Don't be like me. It is an auto immune disease so keep your immune system up to help fight everything in your body.
One other thing: Use cotton only underwear. All the other kinds, even when lined with cotton in the sensitive area, do not allow your sensitive area to breathe. You could liken it to sealing your food in plastic storage of some sort. Your wetter foods will develop condensation on the inside of the plastic. Well, the same thing happens with a woman's sensitive area, because we do have moisture that needs to be allowed to air dry.
Another thing that can help is to wash such delicates using only baking soda then the double rinse. As these are lightweight items, I recommend hanging up to air dry if you have to use shared machines as in an apartment setting or public laundromat setting. The residual from other peoples' use and over use of dryer sheets does get on your clothes, so it makes sense to air dry your delicates.
Maybe it's laundry detergents/dryer sheets...double rinse undies and pants/shorts...coconut oil on the outside of Vulva seems to help.
I have the same feeling for about 7 months now. the burning can get so intense that i cant move and have found ways to soothe it but nothing instant. i too was checked for yeast and bacterial infections and since i am not a virgin i got tested for all std's and they came back negative. i have seen a urologist as well only to tell me that i occasionally have a urinary tract infection but the meds i am given to clear that do not rid me of the raw tender burning feeling in my vulvar area.