For what it's worth, I used to be certain that I thought in words too. Then I moved to a different country and used a second language often enough that I sometimes think in it. I then realized that there are periods where I think in neither my native language nor in my second language, even when I'm thinking. YMMV of course.
This describes my experience nicely too, although I didn't quite realize it until reading this. I was thinking I just thought in words and had a tendency to mix up the bits of various languages I know some words from, but occasionally I have some thought, then for one reason or another become conscious of the thought and get confused which language I was thinking in. Sometimes this even manifests as trying to mix languages (eg at one point I used to struggle to not sprinkle in french and farsi words into normal english, despite speaking english at a native level and only knowing the basics of the other two).
I've always thought of my mental model as an endless conversation with myself, but I think the more fitting description would be a "smooth" series of thoughts which only materialize into language when I explicitly focus on those thoughts as their own thing.
I do also think visually for things that have a visual component though.
Do you find your domain of thought shifts when you do not think with language? For example, do you feel you are able to do complex reasoning without language?
