What about doing what Improving posted about and ask for a photo of him? And maybe one that you could take in his office?

I know what it's like to have T as the major/only source of support. Could you talk to him about your fear of abandonment, particularly in light of this situation? (Maybe you already have?) It sounds like you have a dedicated T if you're allowed to write him daily and he sees you twice per week! Hang in there.