Because of the way I came across my T I did almost all my sessions with her over the phone. Ocasionally I traveled down for an in-person session but found that really weird and awkward after feeling so relaxed talking over the phone! So I know what you mean about it feeling different when you change the setting for talking.

You could jot down some of the things you want to talk about. Don't worry about silences if you have them over the phone. Your T will be sensitive and look after those moments, I'm sure.