Your problem is very likely the chemicals used to treat the fabric. As much as it might upset you to stop sewing for a week, it is probably in your best interest. If you stayed completely away from your fabric for a week, you would know for sure that the fabric is, or is not the problem. If it is not the problem, at least you would know to look for other causes. As much as you are enjoying your quilting/sewing, I hope the problem doesn't stop your sewing !