I am suffering from Terriens degeneration in my left eye from 3.5 years. It took about 1.5 years for doctors to give me a proper diagnoses and confirm the disease.
What you say is typical with advance stages of terriens. I however have a different variant of the disease.
I regularly get PUK (peripheral ulcerative keratitis) attacks. The severity of the attacks varies every time. Some times I get mild discomfort and some times they are extremely painful extremely painful to the point I cannot open the eye at all. By regularly I mean every 10-20 days (twice atleast a month) for the past 2 years consistent. Some time I get a break for a month or two (once or twice a year), with very minor attacks, hair line infiltrate but then it starts full fledge and regularly again.
Besides this I have 24x7 regular discomfort in the eye, eyelid, cornea, where doctors cannot explain a clinical cause. About a day or two in a month my left eye feels like normal like my right eye. Doctors assume the discomfort is because of low grade inflammation, unevenness of the cornea which is causing dryness and bunch of other problems in the eye. They are not sure, so all treatments are trial and error only.
I had been to Germany for consultation. I meet Dr. Thomas Reinhard, Freiburg University Medical Center who confirmed my condition as "Inflammatory terriens marginal degeneration" or Terriens degeneration with an inflammatory factor.
I have some research documents which took months to dig out from various institutions regarding this disease, I don't mind sharing those with you.
As far as I know, this condition is extremely rare and doctors don't know the etiology or mechanism of the disease, plus cure is a far fetch word, there is literally no treatment for this.
Depending on your condition some sort of surgery may be required. You need to see a cornea specialist and get proper diagnoses and surgery (if required) done. For me I have been told to just sit and keep waiting till my entire cornea gets uneven and damaged due to the PUK attacks, they will only then intervene and consider some sort of surgery.