try lengthening your stitch length...maybe 8-10 per inch would loosen that up a bit...put together a small practice piece to work on for awhile so you don't damage your quilt ripping out your stitching...wait until it is going the way you want it then move to the quilt. use the same weight fabrics and same batting (if possible) for your practice piece. personally I hate using the walking foot...i know so many people who use them all the time and will not even consider not using it...i have never had any luck with it i do much better with a regular foot for straight line stitching.
good luck :thumbup: