zooropa, why didn't you call your t before you did the SI? That is what you are supposed to do in DBT. The logic behind the 24 hr rule is that once you SI to cope, you don't need help anymore because you already chose SI instead of using DBT skills. If you want help to use skills instead of SI, then that is when you call T. As Darkrunner said, they don't want to reinforce the behavior so you will not get attention for doing it. Did your T want you to do a behavioral analysis that you can go over with her when you see her again? This way, you can identify what was happeneing and how you can best cope next time.

Also, it sounds like your t really cares a lot about you because even though she is adhering to the rules of DBT, she asks you to call exactly 24 hours later to talk to her. My T wouldn't do that, I know that for sure. I would have to wait until next session. Try not to see it as abandonment, but rather your T doing her best to help you NOT SI in the future. Next time the feelings are overwhelming and you can't remember what skills to use in the moment, call T!