UGHHHHHH......I can very much relate to this, as I had a very close friend (the one who tried to run me over) with similar tendencies. Always some kind of drama to get the attention back onto her.

Ideally, confronting your mom with your concerns that she may try to sabotage your residential program which is very important for you (or, putting it more gently, that she may make her needs a higher priority while you need to focus on ONLY YOU during that time) and asking her to direct all important needs to one of your siblings. I understand it may stir up some backlash, but I've also learned that sometimes boundaries can be set and respected for a while.

I feel badly that you are in a situation where you feel you have to sacrifice so much.

(( HUGS ))