I'm so sorry that you're going through this! I had already been dealing with Erosive oral Lichen Planus for over a year when I got my first 2 Covid vaccines, so I really didn't notice if there was any change in anything. Shortly after that I was put on Prednisone, (for what ended up being 3 months!), so I couldn't get my booster. My Dermatologist tried Prednisone along with a couple other things that didn't help at all, and then I asked about Triamcinalone. (This is going to sound COMPLETELY insane, and if you want to write me off as a total wacko, that's okay, but read this first......One of my cats had Feline Stomatitis which is very similar to Erosive Oral Lichen Planus. I took him to the Vet every 3-4 months for FOUR YEARS for long-acting injections of different medications. He couldn't eat, and he screamed when he drank his liquid diet. One time I took him to a different Vet, and that Vet gave him something totally different --- He gave him an injection of DepoMedrol [Methylprednisolone - VERY similar to Prednisone] and an injection of Vetalog [Triamcinolone]. My cat has not been back to the vet for over a year and a half, he's doing fine, and he's eating canned cat food AND dry cat food, and he's a happy, healthy boy!) SO, I told my Dermatologist that I wanted to try ONLY Prednisone and Triamcinalone. She kept me on Prednisone and put me on Triamcinolone Paste, and the ulcers started getting smaller & smaller........and now they're gone! That being said, I've been off of the Prednisone for almost 2 weeks now, and there's a good chance that the ulcers may come back ------ I hope not, but most of the things I've read say that they probably will.....I guess time will tell. Now I'm wondering if it will cause them to come back when I finally get my Covid booster. I was told that I could get it 2 weeks after I finish my Prednisone. Hmmm....... Anyway, you might want to try Triamcinalone Paste on your ulcers. It's kind of strange stuff -- it's tricky to put it where you want it and get it to stay there! I use it right before I go to bed, and I try to find time during the day to take a short nap, or at least lie down for 30 minutes to 'hold my mouth still' so the medication has time to work.
I hope this info might help you a little.......good luck!
Kathy