quiltmaker101,
Your first quilt class experience is so sad. That was just so very wrong of those ladies! Grrrr!
Here is my recommendation for your 'cure' of this horrid experience. Next time you're at a quilt show or even on line. Get up close and personal with some antique quilts. Wow! Our grandmothers and our grandmothers, grandmothers were not always that precise in their quilt making. They were making working quilts and obviously had lots of practice and some are pretty awesome but there are also those that didn't always have the perfect stitch or the exactly matched points. Trust me. I've looked! After checking out other quilts really close I always walk away with the attitude, "I can do that!" and I usually do. Also, those less than precise seams and quilting didn't take away from the overall look of the quilt at all!
Stick with the art. Soon you too will relax and let your quilts be what they want to be! Quilts know best! :-)