Do you ever just feel like an hour on the calendar that can be added/deleted/moved at will - T's will, not yours?

I usually have weekly appointments. Every week, same day/time. Lately it seems that for some reason or another (T's reason) we have needed to move. 2 weeks ago we had cancel our regular weekly time and she offered another time the same week. I totally acted out and didn't go the other time she offered me. I know this was my way of trying to have some control over the situation. It was a bad move on my part, but I hate feeling like T has all the control (it's one of my "issues") Then, this past week T had a family emergency and we had to miss session. This upcoming week she is taking off for the holiday. I know that hour we are together she is totally with me and cares, but I'm really running up against the whole "I'm just a client. I'm just an hour on her calendar." feeling and it stinks. I know she cares about me, and really I AM just a client. I mean - that is what therapy is, right? I just hate the helplessness of feeling like she can just move me around or take not see me willy nilly, you know? All the while, I still have my crap to deal with. It makes me want to pull away from her - as if to say "I'll show you I don't need you." I don't know. Does anyone else ever feel this way? I hate it. I don't like feeling this way at all.