I have had a similar experience - my one and only emotion (or do I mean feeling) has been anxiety. T would just get me every session to notice my body from toe upwards and identify any sensation I had.

We would stick with the anxiety and focus on it - where it was, what it might look like etc.

Sometimes now (2 years later) I get a different sensation but mostly have no idea what it is.

I do believe being more aware of my body and being able to identify emotions is the thing that is going to take me forward with T - I just trust that it will take time and patience.