The only person who has not found they've made a mistake is one that has never cut or sewn a quilt!! Be happy.. at least your squares that are the wrong size are too big.. it's a lot more of a problem if you had cut some too small! Just set it aside tonight.. and tomorrow when you get up you'll be able to fix the too big squares and then everything will go smoother.. We'll be looking for a happy update.. you'll love doing an Ohio Star once things start falling in place!
That is the one big problem with a June Taylor ruler.. if you happen to get your blade in the wrong slot, you've got several pieces all cut wrong. But I love mine and use it all the time.. such a time saver unless you really goof up and have to go buy more fabric!!!