I wonder if your long term therapist would have had an easier time saying it because you were so young when you started seeing him. It would seem much more like paternal love then. I can imagine that a male therapist might be worried about saying it to an adult female client because she might misinterpret that as "I love you romantically," or "I want to have sex with you." I'm not saying that you would think that about your therapist, but I could see that he might be overly cautious.