I am so sorry. As Redpony and Farmpony have already said (and far better than I can), hang onto what you believe to get through and take whatever time there is and don't hold back how you feel with your mom. Now is the time to leave nothing unspoken, and you may find a deeper understanding and relationship with her. Oh, and it's normal to not always get along with your parent, but glad you love her.
My heart and prayers go out to you both.
Be the kind of woman that when your feet hit the floor each morning the devil says, "Oh crap, she's up!".