Sorry you're having trouble with the end of session. That must be tough. I'm surprised I've had relatively little difficulty with this. Maybe it's because I watch the clock like a hawk, and more or less police myself. The result is that I'm almost always ready to leave when it's time to go.

Session materials feel more or less contained--though I think I'm the one who puts them back in their box, not sure what my T does to help with this. He does give a sevenish minute warning ("we're running up against time") and we can wrap up with something lighter. Chit-chat, sort of. He's also very good at giving some departing words that, for whatever reason, come off very genuine and caring ("it was nice to see you. Take care" etc). He has never extended time, but he's constantly late, so maybe he does with other clients. This is pretty solution-focused therapy, if that makes any difference.

I hope this aspect of your therapy gets better soon. Good luck!