My T once said that it was essential, in his line of work, that he liked everyone he worked with. But he said he didn't like everyone who walked in his door. I asked him how he did it, and he said, "I find ways to like them." I think what he meant was that we all have likable qualities, and as a T he just has to find them. And I really believe this. Even though any specific person might not be particularly likable to me, it doesn't mean that they aren't that way to other people. So a T's job is to figure out what positive aspects there are to each person, whether they're things that are personally appealing to the T as an individual. They are human, just like we are. I think your T is telling the truth. He's not going to say things he doesn't believe. He's trained to find the positive in people and reinforce it. He doesn't make up positive stuff when it isn't there.
Believe him. He's seeing the positive parts of you, whether you can or not, and giving you positive feedback. The fact that he asked the question makes me think that he thinks you don't believe him, that you have a lot of negative self-regard. I think most of us are able to detect when a T is being phony and lying, and they know it. They are all about "authenticity".
I hope you can believe that your T is not just blowing smoke. You DO have positive qualities that people can relate to, and if you keep working to improve yourself, you'll have even more.