If she is a decent person and professional, I doubt she would judge you negatively, more likely that she would be glad that you shared as that can guide her to focus on your true problems rather than surface cover. I guess a T could help to keep the focus on the real issues and challenge you if they are so inclined (unlike mine in the past). I had a few people in my life (not Ts) that were immensely helpful in that way and it always involved calling me out on my BS and avoidance, or the excessive thinking and rumination as yet another way to diffuse things and escape. I also found that the people who were truly good at this and helpful never approached it from a sense of negative judgment and superiority (those are just signs of one's insecurity I think) but because they were genuinely interested and actually understood me rather than misunderstood or projected their favorite ideas. I grew up with a father like that so it is easy for me to recognize when it is truly constructive, but I think one can learn it as well. I really think that therapy can lead people onto many false tracks and useless investigations if it is not approached with a critical attitude. But I think only the client can really lead that, Ts usually do not initiate scrutiny unless they become defensive for their own sake. You see, one reason for sharing uncomfortable things with the T is exactly to see how they respond. If the responses are not helpful, you can look for someone else already knowing what did not work.

I definitely had that issue with therapy-related stuff occupying my mind excessively. Many people on this forum experience a version they describe as attachment, for me it wasn't that, it was literally getting stuck in analysis paralysis, which I am very prone to by default and have always been. I often experienced it as very stimulating and gratifying - I like to dissect things and find patterns in everything, to understand how things related inside out, and for a while it felt like therapy was the perfect playground, doing it with someone else interested and apparently trained to do just what I like to do on my own as well! But it wasn't really helpful and did not solve anything for me, it was mostly just another introspective journey without substantial practical benefit.

What you described is very much how I tend to exacerbate my anxiety as well. My baseline anxiety is really not that bad but I can expand it and make it unbearable with avoidance and with unhealthy habits, which never actually work because I am not dissociative and those things never get out of my awareness, it is just like taking a pain pill that does not even work well and will wear off in a couple hours. If the strategies help in critical moments, only if temporarily, I think it is good. But eventually it is better to get to the roots rather than just medicating the symptoms, if possible. I think this is why Ts generally like to explore the past, because the roots are often there. But not always, sometimes they are just a physiological condition more than anything else that generates the thoughts and feelings, a brain that tend to be hyperactive and overstimulated. I think anxiety is often very much like that, especially generalized anxiety. Then we project it into all sorts of external things or try to manage it with actions and experiences that alleviate the anxiety in the moment, for a short while. It ultimately works much better to learn to tolerate it and not get paralyzed by it. I think many people who suffer with excessive rumination and a distractible mind can also benefit from medications, but those effects often don't last and then the meds need to be re-adjusted or changed.