Usually, FA info is released with the decision. It may be more generous than you expected or it may be less.
If you feel that your financial situation was misunderstood, you can go back to explain and request more. You may or may not be successful, particularly if you and the school do not agree on what are necessities for your family and what "sacrifices " you may need to make.
You are so close to getting this information that there is little point in planning a "negotiation " now. Good luck tomorrow!