returning to work drama. help

i posted earlier in week how my coworker wants my replacement hired.. has been trying to psyche me out saying come back part time/its going to be hard for you etc.

well i go back soon and am going in this week to start transitioning.  my boss wants me to take some of my coworker's load as she is overwhelmed.  we work in a school  divided into lower and older as counselors.  i would have to take some of the older, which makes no sense because im never with them.  she has more students number wise, but the issues are just as bad if not worse at times.

 i have a pit in my stomach bc its not fair but i dont know how to handle it  considering ive been out for a while.we are having a meeting about it.   i also typed up my day to day and emailed it earlier today  to show them that i have alot on my plate as well.. no response.  im sure they are waiting for this meeting?

any suggestions? im not even back from leave yet and im getting stuff dumped on me