Grovers is usually transient lasting 6-12 months. Hopefully so for you. I've been using Triamcinalone for years as a topical, but it can make the itch worse for a while. Through a Facebook group I discovered Avene balm recently. For me, it works as well as the triamcinalone and it's not a steroid, but others haven't had as good a result. My spots want to act up at night before bedtime, of course. When the Avene doesn't cool it quickly enough I fall back on my old standby, which I discovered around 15 years ago. It sounds very counterintuitive, but it works for me. After using the Avene balm or triamcinalone, I blast the spots with a hairdryer on high speed, high heat. You have to hold it on the spot until the skin is as hot as you can stand it and it somehow deadens the sting. On a bad spot I may have to blast it a second or third time until the itch stops, but then it's gone for the night. If you are in the midst of an initial outbreak with rash all over, it may not work for you.

I totally understand your desparation. I've been in your shoes.
I haven't had my chronic GD return since I experiemented with an at home heavy metal detox about 3 1/2 years ago. Google the assocation between- Alzheimer's, Parkinson's and Grover's Disease and heavy metals. On this Mayo site from another blog I learned about using cilantro to chelate heavy metals, this detox helped a bit over 40% of us that tried it and was documented on our Mayo blog with about a group of 10 of us. Use approx 1/2 bunch fresh or fresh frozen cilantro, blend it up with other ingredients or as I came to accept, simply blend it with water and chug it down like a nasty tonic. After 3 weeks I realized my month old break out was stalled. After 6 weeks no new activity for sure and itching was lower, but it took over a half a year for most scabs to fall off. I I could feel the little bumps under my skin if I pressed on the skin, but they didn't hurt as much. A full year for all the scabs to break off, if I scratched them off thinking they were dead skin they came back, but were not itchy. It took three years my skin feels normal and the little under the skin bumps are totally gone. I could have a back massage and enjoy it today.
I did drink this cilantro tonic daily for 6 months, whereas most who got results after 1-2 months stopped after 3 months. I only make a tonic now about twice a year. Now over 3 years later still clear.
My history- Allergic Contact Dermatitis since age 50. Perioral Eczema age 69. GD began age 67, with the intial outbreak lasting one full year and covering upper and lower front and back torso, with sides clear. Subsequent breakouts didn't cover as much of the upper torso areas. My GD was not only itchy but terribly painful. I couldn't lean back in a chair and had to drive hunched over.
Sleep was fitfull and restless but I trained myself to never move in bed; I could only lay on my blessedly clear sides.
After my initial one year of GD breakout I had a consistant pattern of 6 months of dormancy and 6 months of active GD. No prescription ever made any difference and with 3 dermatologists I tried every suggested worthless prescription on the market, everything you mentioned plus others. I never needed anti-biotics because my papuales never became infected pustuales. Today I can even take a hot shower and enjoy it, before my skin needed cool water at the lowest volume possible bccause any pressure hurt.
Do some internet research of the relationship between heavy metals and GD. I should also point out that 2 1/2 years ago I gave up all processed sugar. I had given up all alcohol 2 years before that out of desparation trying to help my body be pain free. Perhaps that's helping in the remission, but it's the cilantro that definately made the differance for me and others. The result of giving up sugar (I never was overweight or ate more than occasional desserts but hidden processed sugar is in so many foods) was a dramatic lowering of my internal inflamation which were causing other issues thoughout my body. Hoping to be free of pain can give you this will power. Today at age 74 I'm back to all my outdoor activites. Sure a few aches and pains from arthritis, but I'm basically pain free and itch free. BE HOPEFUL- Keep searching for answers.