Can you just take a moment at a time? You know you can manage 1 day not seeing your T as that is what you have been able to do. So can you tell yourself that you managed yesterday and so can manage today?

Yes I would definitely discuss with your T. I have been reading some stuff about mental representations that we carry in our head of people. Maybe when you were going twice per week, these representations were being reinforced so that they didn't fade away. But with a longer break between sessions, these representations do become fader and harder to hang on to which may then explain the feelings of increased anxiety. Sorry may be well off the mark here, but I have been able to relate to the reading I did about this.

Take care - Soup