Earthmama,
This happened to me a few weeks ago, and I know exactly how you feel. I think it hurts more in this situation because it brings to the forefront the fact that we care more about our Ts than they do for us. Although they do care about us, it is not usually in the way nor intensity that we would like. Our worlds seem to revolve around them and we would NEVER make an error like this that included "forgetting" them. My schedule is screwed up for the next three weeks or so. So, I went ahead and scheduled my normal appointments through June or July so I won't have to deal with this again. I know it's painful. It would be good to tell your T how you feel, but also tell him that you want to be put on his schedule for your regular time as far in the future as you can.

((((((Earthmama)))))))))
I hope things go well Take care.