It is indeed amazing to be able to care enough to miss a T between sessions :-) Good for you! I know for me I tend to try to avoid feeling that sense of loss and longing. It feels so unnatural for me. Like if I miss T, there is something wrong with me. But I think it is a good sign of healing. Healthy people form attachments to others in society. It is what makes societies and families work. For me, I have spent so much time as a child being hurt by the people who I felt should have loved me, family and friends, that I decided to not allow myself to feel those natural connections with others. The more distance I could maintain between me and "them", the less I would hurt when they would leave, die, or say something that could hurt my feeling.
With T I am learning how to safely allow myself to care about another person. I find myself wanting to know how he is doing. For me, wow, that is a huge step to healing. My "friends" from the past never were too close to me because I really never bothered to ask them how they were doing. I did not want to know. I told myself I cared about them, but I did not realize I was in fortress mode. Then when they left me, I didn't care about that either... Or at least that is what I told myself.
A good T will allow us the safe relationship practice we need. I am glad you posted this and very glad you enjoy the "luxury" of missing your T :-)