Re: scar tissue
What options have been presented to you? Scar tissue formation after any surgery is virtually guaranteed, but depending on the amount and location, removal of some tissue might be possible. If surgical intervention is not practical, that pretty much leaves you with pain management. There are numerous other medications that are effective at reducing nerve pain, though most of them were not developed for that purpose. Several anti-depressants, anti-seizure drugs, and anti-anxiety drugs may help reduce your pain to tolerable levels. I don't know what your Neurontin dosage is, but it is often not effective unless you are taking over 3,000 mg a day. If the Neurontin is helping you, you might be able to increase its effectiveness by adding acetaminophen (Tylenol,) as both act on GABA levels.
If oral medications don't provide adequate relief, you might benefit from Epidural Steroid Injections (ESIs) or nerve blocks injections. These may provide months of relief per injection.
You may also be a candidate for a nerve stimulator, or possibly and intrathecal pump (most commonly referred to as a morphine pump, though many different pain killers are usually used.) Brain stimulators are a last resort, with Deep Brain Stimulation (DBS) being the "last" last resort. But don't start thinking of last resorts right now, because there are many things that can be tried. Ask your doctor to list all the possible treatments, and then ask for the doctor's treatment plan.
Don't be surprised or upset if your doctor recommends a pain management specialist, particularly if surgery is not a reasonable option. Good luck, and please report back on what you find out. You shouldn't have to live in severe pain while there are so many possible therapies. Even things like accupuncture are worth considering.