Feline Acne Nightmare!

I have a 6 year old Mane Coone with severe Feline Acne. I am at a loss as to what to do next. We have tried 3 rounds of antibiotics, 2 cycles of steroids, topical antibiotics as well as a chlorohexidine flush. We think the acne was caused by his drinkwell fountain (plastic), so we got rid of it. He now drinks water out of a class bowl and eats off of ceramic dishes. We have also switched him to a high quality single source protien diet incase his acne is caused my a food allergy. Additionally, we have tried warm compresses. Despite all of this and 2 months time, my fluffy love still has pustuoles. I am up with him off and on all night, trying to make sure he doesnt scratch one open (they tend to get infected.) We tried a cone but it was not effective and just stresses him out. We have sedatives for when hes in pain. I guess I am writing this to see if anyone has any ideas on what we should do next? Id also like to hear if anyone one else has experienced this? We're just not sure why hes not improving much.

Mia had feline acne this last summer. I threw away the ceramic bowls (they can get little groovs in them over time that bacteria can hide in ) and got stainless steel ones. I also washed them twice daily. The only other thing I did was toclean her chin in the a.m. and pm. with stridex (otc acne treatment for people). This was all on recommendation from my vet. It was gone within a month.

Hope you are able to get control over it soon. I know it is very miserable for a cat.