Yeah, I was going to suggest highway hypnosis, too. As starry night pointed out, it's not uncommon.

I would say that your level of stress can cause all kinds of issues--memory, attention, mood. I've had bad patches when I've ended up in the middle of an intersection, going on red, thinking it was green, and other traffic/car issues. I don't think it matters why, so much as noticing that it's a problem and doing things to be present and mindful.

I'm sorry you lost your good therapist. Is that certain? From what I recall, the clinic dropped you because you kept canceling your appointment with your therapist (sorry if I got that wrong). Is there someone who can mediate between you and the clinic to get back in? Or maybe you have too much of a disagreement with your therapist about her treatment plan to do that? Either way, I hope you can find some resolution whether you go back or not. Your first therapist has always been toxic for you. I hope you can find better support. You sure deserve it.