I get three weeks over Christmas, too, and much longer summer breaks. It is not strange or bad to get the feelings you describe. Not everybody feels like that but many people do. I find it very difficult to get through the breaks and they definitely trigger a sense of abandonment. Before the ten-week break last summer I started dreaming about my dad, who died very suddenly a few years ago, and I don't think those dreams were coincidental.

Again, it is not a bad sign that you have these feelings. It sounds like therapy is meaningful for you, and that's not a bad thing. The first session(s) after a break, even a short break, can be a little weird and it can take a little while to get the connection back. That, too, is common. And it can be a very good thing to discuss with your therapist.