I know how you are feeling. Fabric companies should be required to post a warning on all fabrics that bleed to prevent situations like you have. Or, we should all stop buying these brands of fabric. I now wash all of my fabrics
before using them along with a piece of white fabric so I will know before using that it will bleed. I have also stopped using frabic brands that bleed. I hope someone has a solution to fix your quilt without your having to take it apart.