OLP or Lichenoid reaction? It curable?

So, I am facing rough buccal mucosa since 2 mot hs after hyperpigmentation started up, slowly it turned into rough areq throughout my inner cheeks. Dentists say its simple melanosis and dermatologists say its OLP. But I don't have any ulcers or burning/itching. Just when i wake up i feel cheeks are abnormally dry, after eating and drinking water it feels so dry. Thats all, attaching an image of both left and right side, also there some pigmentation under lips too. I am 70% sure this started after my first dose of covaxin, prior to that it wasn't there... Anyway, my question is can a biopsy determine whether its OLP or Lichenoid reaction to something? And if its Lichenoid reaction, is it curable? And can it determine which type of OLP it is(if it is, which i wish never happens).