There is also another possibility that no one has mentioned here specifically. Many times, when an OP is reading through responses, especially if it's a busy thread like so many are in Psychotherapy or Relationships, while processing all that they are reading, it could be very easy to miss a thanks or a response to a poster. This does not mean that the OP found anything you said outside of being supportive. It means they may have just missed responding or thanking you for your post. I've done it myself when I've been in a hurry or very stressed and I'm processing.