Have you contacted the designer that was listed??
Design and Instruction by Larene Smith
The Quilted Button, Mission Viejo, CA
I am not familiar with this quilt store but Hoffman main office is also in Mission Viejo.
Do you live near a quilt shop that you could ask for help? Yes, you did pick a very difficult pattern. A newbie doesn't always have accuracy with their 1/4" seam so that might be your first problem. Accuracy of cutting may be the second problem.
If you lived near me in So CA, I would show you how to draw the actual size of each section of this quilt so you could check the difference with what you have sewn. If you have a scanner, I would print the quilt pattern finished and then blow up the section if you are not good at drawing. Take each section and finish them. Good Luck. PM (personal message click on my avatar) if you have more questions. Don't feel that you are sinking. We as a board will try to help you. Welcome to the board.