I have very dry eyes and 2 bouts of filamentary keratitis-in both eyes both Xs. Both Xs I responded to mucomyst, or acetylcysteine
eye drops 4 Xs a day. It’s costly, and has to be obtained from a compounding Rx. It can run close to $100 a bottle, and is only good for 30 days. But it worked both times. Good luck. Eye pain is so hard to treat. About all that helps with that searing, burning pain are opioids, but health care providers are so afraid to recommend it. Sigh. FYI, I tried Restasis, but I got no relief from it.