Christy,
this CAN be fixed relatively easily. Before you start, I presume that your grandfather (and parent) are already listed on the tree? If not please add them in the correct place as children on Anna.
You can change who your parents are by clicking "Edit Profile", either in the profile or in the tree. You will then see a tab that says "Relationships". The first field there is titled "Parents".
If you click that, you should see a list of suggested parents. This list is limited in length, so you might need to make this correction in stages. If you see your actual parents in the list, select them, click the Save button (at the bottom) and you're DONE!
If your parents are NOT shown in the list, select your grandparents, click save, and repeat - the list of parents should be updated now...
Shmuel-Aharon Kam
Geni Curator