Sorry you’re going through this.
Have you been to a major pain clinic (university or otherwise) and spoken with someone who has a lot of experience managing chronic pain patients? If not then that might be a good step. Ultimately it’d be ideal to find someone who has worked successfully with similar issues to your own.
What does the quoted 85% “success rate” really mean? And what does the other 15% look like? What are the sample sizes they are working with?
Neurectomy may help but it is ultimately unpredictable, it is not a guaranteed way to remove pain. The most obvious example is people who lose a limb and then experience phantom limb pain despite the fact there are no nerves or limb to feel the pain. A groin neurectomy also can have other unintended side effects that you can read about on these forums and elsewhere.
Dr David Chen at UCLA has substantial experience with neurectomy and may be a good resource for tracking down knowledge and study data. You might try looking around on NIH as well for outcome studies.
It might be wise to try various less invasive approaches first. Repeat nerve blocks, ketamine transfusion therapy, longterm vitamin C and alpha-lipoic acid, etc etc