I do hate when they use the therapist/client roles to explain things (like my T giving it as a reason why he doesn't share where he's going or when he says "it's a professional relationship"). I'm sure she doesn't mean it as a vacation away from you specifically But it's really hard being thought of as part of their "work," I know.

It's good she is saying that it's OK for you to grieve. But I see how that can also feel like she's putting it all on you rather than taking some of responsibility for her vacations and the effect they have on you (and presumably on other clients). Especially when she's taking more time off now than she did in the past. Mine has apologized (particularly with times he's had to do virtual), which has helped.

I think you do need to talk about this some with her. Maybe not right now, but at some point. I'm guessing it triggers feelings of abandonment, along with feeling less important and being a burden, as you said. Maybe she doesn't fully understand how it feels for you? Showing her some of what you've written here and in other posts might help.