Hi ECHOES,

Maybe your being too self critical...
Your T didn't sound like he was being critical of you, but just doesn't want to get into something really heavy at the end of a session as it's not good for you.

It's rather normal for running over time for various reasons, even if a person doesn't have problems in respecting boundaries.

Sometimes in my sessions, it can take me awhile into session to start to feel comfortable enough to discuss the difficult topic.
This is due to the disorders I'm in therapy for in the first place--anxiety disorders and ADHD. Either I'm too anxious, or my mind is unfocused from the ADHD (or both) and my T can't get me back on track for some reason that day. I've been known to completely derail more than one therapy session if he's unable to stop me and redirect.

Every once in awhile this results in inadvertently discussing a heavier topic toward the end of session, in which case my T makes sure that I don't run more than 5 minutes over. If it was really serious, he'd recognize that and deal with the more immediate problem.

When I first started getting comfortable with my T when I began therapy, I realized that "oh yeah, I need to open up more and actually discuss the problems." So...I'd touch on a volatile subject, and when it got too heavy and pushed into deeper territory, I'd actually INTENTIONALLY try to derail the whole thing...T was on to me pretty darn quick though (which is actually a good thing).

All sorts of reasons why the session can go over and/or get derailed.

Really though, what T who has specialty training in adult ADHD keeps a cannister of brightly colored Tinker Toys right in front of the patient...