I would not be surprised if that is the case. I briefly took doxycycline and it cleared up but I also stopped eating oats at the same time so hard to say what did it. And I understand doxy is nasty stuff. I had to take it with yogurt because it messed up my stomach so badly. 

I would hesitate to recommend tetracycline or any antibiotic as a long term therapy option because of the negative impact it has on the gut biome. I took it for years as a teenager for acne and I'm convinced it was a contributing factor in my having developed celiac disease.

Welcome to the forum, @Pamp8, I stopped foods high in iodine, like dairy and eggs, kelp and iodized salt.   I take Niacinamide also called Nicotinamide or Vitamin B3.  I haven't taken the tetracycline with it.   It seems to make the blisters disappear quicker. I also use tallow balm, a cream made from beef fat, which has been used for thousands of years.  It is absorbed into the skin better than creams made from plants.  It helps prevent or lesson scarring.  See the study below. Two Cases of Dermatitis Herpetiformis Successfully Treated with Tetracycline and Niacinamide "The combination of tetracycline and nicotinamide can be recommended as a useful therapy for patients where dapsone is not available or for patients who do not tolerate dapsone." https://pubmed.ncbi.nlm.nih.gov/30390734/

First off, I’m so sorry you’ve been dealing with this for so long—being sick for half your life is unimaginably tough, and it’s huge that you’ve finally gotten some answers. A celiac diagnosis can feel overwhelming (especially on top of being vegan!), but it’s also a turning point. Your body is about to start healing, and that’s hopeful! This article has some detailed information on how to be 100% gluten-free, so it may be helpful (be sure to also read the comments section.):    

Yes, it is likely your villi healed, but if you are exposed to gluten regularly again the damage will likely come back and cause some potentially serious health issues.