I agree with the others - you probably want to rip it out and start over. Ugh! No fun at all, but this is a learning experience (up until the very end, I expect!). Did you pin baste your quilt sandwich? I personally like to use an adhesive spray (get the kind for quilting, it washes out), but I also pin every foot or so - especially along the edges and the corners, as you sometimes don't get the spray evenly over your work. I would also use the walking foot. It makes a huge difference! You may still get some stretching though, so keep your eyes open and kind of ease the fabric on top all the way along your stitching. You'll get less "bubbles" that way.