Are you able to see a doctor to have them do some kind of brain imaging? If you have no history of studying as a child, the reason it would develop as an adult as if your brain incurred some type of trauma. I would have them check things out to be safe. Is your words switching around due to dyslexia? Some other things I'd look at are apraxia- try emailing or messaging Jordan LeVan to see what he thinks - https://www.instagram.com/fightingformyvoice?igsh=ZGN3YWw3YTV6dWxk He's a speech therapist and has apraxia and may be able to help point you in the right directions. Would know a lot better than randoms online