Welcome aboard!! I'm sorry your having such a difficult time with your first project. Can you tell us what pattern your using? Unfortunately pre-cuts are notorious for their inconsistent cutting, some are too big, others too small, some are just right and it happens to all manufacturers. It's always advisable to measure before you begin a project, so you know what your getting into. Also check your 1/4 in seam allowance.
Others will be along shortly with more solutions!!