The rotation business likely won't improve for a bit. I think they've mostly been spending a good amount of time as of late working on helping current 1st years that didn't match into their first or second choices get into something they're wanting and not the leftovers of the leftovers (and unfortunately for y'all, current students > future students). So all I can really advise is to just sit tight a bit longer, which I know y'all have already been doing. Unfortunately, what y'all are going through is a completely new process (as they've never let incoming students choose their rotation sites before matriculating) and like most things that involve bureaucracies trying to do something new, there's a lot that has to get hammered out on the fly.
DbDan is right about the COA. So, probably tack on an extra $2-3k for your COA next year. Also, keep in mind that the school adds in some "padding" for your COA, and you don't have to and shouldn't borrow anymore than you need to (I'd suggest sitting down and figuring out a reasonable budget ahead of time either by yourself, with your parents, SO, etc.).