life will get better sooner or later..

i shouldn't give up just yet

so i lended my mother a lot of money around February and she told me that she would pay me in a few months.  The money was supposed to go to my security deposit to the new school i am transferring to.

My registration day is in a few weeks and every time I bring up the topic about the money to my mom, she just ignores me and looks sad.
I don't understand why she is being like this.  Obviously she doesn't have the money to give me..
but if I don't pay for my security deposit, I won't be able to go to the school this year...
>_<

i don't know what to do