I had never heard of IC until you mentioned it. It seems the primary cause is inflammation, caused by food triggers or not emptying your bladder all the way. Also, seems they don't have a cure, just some work-around controls.
Have you tried any of the natural cures for inflammation? Earth Clinic is one of my favorite sites to find out what others are doing.
https://www.earthclinic.com/cures/bl...infection.html
I have a lot of inflammation in my body, but thankfully, not in my bladder. I have added Tumeric with Peperine (black pepper), several natural products for joint and knee pain, and currently am working on getting fungus & yeasts out of my system by using DE & Oil of Oregano (capsules).
You didn't say anything about inflammation in other parts of your body. You haven't said if you have tried cranberry juice or capsules. Those are the old timey go to for bladder inflections/cystitis. They have helped many people control bladder problems.
Good luck with your quest for health!
Forgot to mention that my husband and I have added the Golden Raisins soaked in a Juniper Gin to our anti-inflammatory style of life. I do believe it is helping some with our overall health. Due to problems with digestion for years, I can't do acidic foods either.