I guess I would ask, how is it going? Usually CBT doesn't take that long. It's usually a short course. When it takes a long time, it might mean it's not working and a new therapist might not be a good idea. I don't know anything about the ADHD part with CBT, so I'm guessing that's a different kettle of fish, but for anxiety, it's usually "supposed" to work in a shorter period of time than talk therapy, which can take much longer or even a lifetime. But that would be my first question, do you think this therapist is really doing the trick for you. Because that's a long commute for a short session. If it were me, I'd find another therapist just because you have other things to do and might end up missing part or all of many sessions, but you get to decide. Sometimes you find just the right therapist and that makes it harder, because it's hard to find a therapist that actually helps us not need to see one anymore because we've fixed our problem.
I think for pragmatic reasons you should seek a new CBD therapist. Can your current therapist recommend a different therapist. How do you feeling about asking?