I wasn't clear after reading if you were cancelling an appointment or actually terminating. If it is the latter, I would say it up front. Then it's pretty obvious that you won't be at the next appointment.

However, I think the issue is that you aren't talking in therapy, and you need some reassurance that's it's okay to be that way, You just ask for that reassurance. Are you hoping your therapist will call? They may not. Get ready for that.

If you are terminating, the therapist really can't ask you to come back.