I bet mine is worse than yours. I just did straight line quilting outlining blocks on my quilt but I did it without a walking foot (since I don't have one for my Bernina yet). I thought I was doing great until I hung it up on my design board and saw how wonky it make my border. I have a one inch border and then a 3 inch one. Then inside of the 1 inch border is crooked now. I make two mistakes. Not using a walking foot and quilting on the across the bias of my half square triangle. I am so bummed. I am hoping if I wash and block it I may get it to straighten out. I am still very new to domestic machine quilting. I just can't seem to get the hang of free motion yet. I bet it would have been better than this though.
so I feel your frustration.