Mouse,
I can totally relate. When this happens with my T, it brutally reminds me that he is totally in control of the relationship and can decide when to see me and when not to see me. I also am reminded that he doesn't have as much vested in the relationship emotionally. Both of these issues stir up some major emotions.

Wouldn't it better if T's would say, I would like to go on vacation with my family, but I won't if it is going to negatively affect you in any way. I think I would be able to say yes, I give you permission to go (with a reasonable time limit) and not be so upset when he was gone, LOL. Of course, no T would ever abide by this because they would probably never go on vacation. I wonder if they miss us when they go.

Take care of yourself and know that you are not alone!