I agree, chin up, enjoy yourself in your adventure with quilting... you will improve with practice. Save the quilts that you aren't happy with for the car for the kids to keep warm on cool nights, or to use in the park or on the beach.
As far as SITD, try a stitch in the ditch sewing foot, it does help, but if you don't have one and not ready to buy one maybe to discover that it doesn't help you, use a decorative stitch to go down the seam.
warm quilt hugs, sue in CA