All the suggestions above as well as starching starching and starching more starching. I find that my accuracy improves when I slow down my sewing, starch starch starch, and take my time cutting and take the time to enjoy the process rather than rush for a finished product. Do you have all the blocks cut? If not perhaps you can start over, others will come along with far more experience, but I appreciate and understand your frustration, hang in there!