How do you know she is going on a trip with her bf? Did she tell you that? It's all well and good saying it's not about her, when a disclosure like that kind of makes it about her. Especially when you have been so badly triggered around bf stuff with her in the past.
I'm not sure whether or not this is useful to you, but I want to say your feelings about her and the relationship are normal and common; I don't always like your T's mixed messages regarding closeness/distance in the relationship. Please remember there's nothing wrong with the way you feel.